diff --git a/.gitignore b/.gitignore
index 45afd8fef7f0..37c66b084feb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,6 +70,8 @@ packages/babel-standalone/babel.min.js
 /eslint/*/LICENSE
 !/packages/babel-eslint-plugin/LICENSE
 /.vscode
+# local directory for VSCode Extension - https://marketplace.visualstudio.com/items?itemName=xyz.local-history
+/.history
 
 /dts
 
diff --git a/eslint/babel-eslint-parser/src/configuration.cjs b/eslint/babel-eslint-parser/src/configuration.cjs
index 5cf2e5cc4fa4..11da9fc6c4bf 100644
--- a/eslint/babel-eslint-parser/src/configuration.cjs
+++ b/eslint/babel-eslint-parser/src/configuration.cjs
@@ -11,7 +11,7 @@ exports.normalizeESLintConfig = function (options) {
 
   return {
     babelOptions: { cwd: process.cwd(), ...babelOptions },
-    ecmaVersion,
+    ecmaVersion: ecmaVersion === "latest" ? 1e8 : ecmaVersion,
     sourceType,
     allowImportExportEverywhere,
     requireConfigFile,
diff --git a/eslint/babel-eslint-tests/test/integration/eslint/config.js b/eslint/babel-eslint-tests/test/integration/eslint/config.js
index 989e9a8287d0..f0a406d251ee 100644
--- a/eslint/babel-eslint-tests/test/integration/eslint/config.js
+++ b/eslint/babel-eslint-tests/test/integration/eslint/config.js
@@ -21,4 +21,23 @@ describe("ESLint config", () => {
     });
     expect(messages.length).toEqual(0);
   });
+
+  it('should allow ecmaVersion to be "latest"', () => {
+    const linter = new eslint.Linter();
+    linter.defineParser("@babel/eslint-parser", parser);
+    // ImportDeclarations result in a parser error if ecmaVersion < 2015 and sourceType != "module".
+    const messages = linter.verify('import { hello } from "greetings"', {
+      parser: "@babel/eslint-parser",
+      parserOptions: {
+        ecmaVersion: "latest",
+        babelOptions: {
+          configFile: path.resolve(
+            path.dirname(fileURLToPath(import.meta.url)),
+            "../../../../babel-eslint-shared-fixtures/config/babel.config.js",
+          ),
+        },
+      },
+    });
+    expect(messages.length).toEqual(0);
+  });
 });
diff --git a/jest.config.js b/jest.config.js
index 2a03ce4e4202..276e156144d9 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -21,6 +21,7 @@ module.exports = {
     "/test/helpers/",
     "<rootDir>/test/warning\\.js",
     "<rootDir>/build/",
+    "<rootDir>/.history/", // local directory for VSCode Extension - https://marketplace.visualstudio.com/items?itemName=xyz.local-history
     "_browser\\.js",
   ],
   testEnvironment: "node",
diff --git a/packages/babel-helper-compilation-targets/src/index.ts b/packages/babel-helper-compilation-targets/src/index.ts
index c4077623583b..2919080b86d7 100644
--- a/packages/babel-helper-compilation-targets/src/index.ts
+++ b/packages/babel-helper-compilation-targets/src/index.ts
@@ -154,8 +154,11 @@ function generateTargets(inputTargets: InputTargets): Targets {
   return input as any as Targets;
 }
 
-function resolveTargets(queries: Browsers): Targets {
-  const resolved = browserslist(queries, { mobileToDesktop: true });
+function resolveTargets(queries: Browsers, env?: string): Targets {
+  const resolved = browserslist(queries, {
+    mobileToDesktop: true,
+    env,
+  });
   return getLowestVersions(resolved);
 }
 
@@ -217,7 +220,7 @@ export default function getTargets(
   }
 
   if (browsers) {
-    const queryBrowsers = resolveTargets(browsers);
+    const queryBrowsers = resolveTargets(browsers, options.browserslistEnv);
 
     if (esmodules === "intersect") {
       for (const browser of Object.keys(queryBrowsers)) {
diff --git a/packages/babel-helper-compilation-targets/test/browserslist-extends/browserslist-extends.spec.js b/packages/babel-helper-compilation-targets/test/browserslist-extends/browserslist-extends.spec.js
new file mode 100644
index 000000000000..876f30777eb0
--- /dev/null
+++ b/packages/babel-helper-compilation-targets/test/browserslist-extends/browserslist-extends.spec.js
@@ -0,0 +1,37 @@
+import { dirname, resolve } from "path";
+import { fileURLToPath } from "url";
+import getTargets from "../../lib";
+
+const currentDir = dirname(fileURLToPath(import.meta.url));
+
+const oldEnv = process.env.BROWSERSLIST_DANGEROUS_EXTEND;
+
+beforeAll(() => {
+  process.env.BROWSERSLIST_DANGEROUS_EXTEND = true;
+});
+
+afterAll(() => {
+  process.env.BROWSERSLIST_DANGEROUS_EXTEND = oldEnv;
+});
+
+it("pass env to configs used with extends", async () => {
+  const actual = getTargets(
+    {
+      browsers: [
+        `extends ${resolve(
+          currentDir,
+          "fixtures",
+          "@babel",
+          "browserslist-config-fixture.cjs",
+        )}`,
+        "chrome >= 71",
+      ],
+    },
+    {
+      configPath: currentDir,
+      browserslistEnv: "custom",
+    },
+  );
+
+  expect(actual).toEqual({ chrome: "71.0.0", firefox: "75.0.0" });
+});
diff --git a/packages/babel-helper-compilation-targets/test/browserslist-extends/fixtures/@babel/browserslist-config-fixture.cjs b/packages/babel-helper-compilation-targets/test/browserslist-extends/fixtures/@babel/browserslist-config-fixture.cjs
new file mode 100644
index 000000000000..b6108c2910f3
--- /dev/null
+++ b/packages/babel-helper-compilation-targets/test/browserslist-extends/fixtures/@babel/browserslist-config-fixture.cjs
@@ -0,0 +1,4 @@
+module.exports = {
+  custom: ["firefox >= 75"],
+  defaults: ["chrome >= 5"],
+};
diff --git a/packages/babel-helper-create-class-features-plugin/package.json b/packages/babel-helper-create-class-features-plugin/package.json
index a217735112f6..a5a0f3e36148 100644
--- a/packages/babel-helper-create-class-features-plugin/package.json
+++ b/packages/babel-helper-create-class-features-plugin/package.json
@@ -31,6 +31,7 @@
   "devDependencies": {
     "@babel/core": "workspace:*",
     "@babel/helper-plugin-test-runner": "workspace:*",
+    "@babel/plugin-syntax-class-static-block": "^7.14.5",
     "@babel/preset-env": "workspace:*"
   },
   "engines": {
diff --git a/packages/babel-helper-create-class-features-plugin/src/fields.ts b/packages/babel-helper-create-class-features-plugin/src/fields.ts
index 695979cdd11f..9d8b386aa91f 100644
--- a/packages/babel-helper-create-class-features-plugin/src/fields.ts
+++ b/packages/babel-helper-create-class-features-plugin/src/fields.ts
@@ -1,6 +1,6 @@
 import { template, traverse, types as t } from "@babel/core";
 import type { File } from "@babel/core";
-import type { NodePath, Visitor } from "@babel/traverse";
+import type { NodePath, Visitor, Scope } from "@babel/traverse";
 import ReplaceSupers, {
   environmentVisitor,
 } from "@babel/helper-replace-supers";
@@ -58,7 +58,7 @@ export function buildPrivateNamesMap(props: PropPath[]) {
 export function buildPrivateNamesNodes(
   privateNamesMap: PrivateNamesMap,
   privateFieldsAsProperties: boolean,
-  state,
+  state: File,
 ) {
   const initNodes: t.Statement[] = [];
 
@@ -165,6 +165,7 @@ interface PrivateNameState {
   classRef: t.Identifier;
   file: File;
   noDocumentAll: boolean;
+  innerBinding?: t.Identifier;
 }
 
 const privateNameVisitor = privateNameVisitorFactory<
@@ -188,9 +189,28 @@ const privateNameVisitor = privateNameVisitorFactory<
   },
 });
 
+// rename all bindings that shadows innerBinding
+function unshadow(
+  name: string,
+  scope: Scope,
+  innerBinding: t.Identifier | undefined,
+) {
+  // in some cases, scope.getBinding(name) === undefined
+  // so we check hasBinding to avoid keeping looping
+  // see: https://github.com/babel/babel/pull/13656#discussion_r686030715
+  while (
+    scope?.hasBinding(name) &&
+    !scope.bindingIdentifierEquals(name, innerBinding)
+  ) {
+    scope.rename(name);
+    scope = scope.parent;
+  }
+}
+
 const privateInVisitor = privateNameVisitorFactory<{
   classRef: t.Identifier;
   file: File;
+  innerBinding?: t.Identifier;
 }>({
   BinaryExpression(path) {
     const { operator, left, right } = path.node;
@@ -204,6 +224,10 @@ const privateInVisitor = privateNameVisitorFactory<{
     if (!privateNamesMap.has(name)) return;
     if (redeclared && redeclared.includes(name)) return;
 
+    // if there are any local variable shadowing classRef, unshadow it
+    // see #12960
+    unshadow(this.classRef.name, path.scope, this.innerBinding);
+
     if (privateFieldsAsProperties) {
       const { id } = privateNamesMap.get(name);
       path.replaceWith(template.expression.ast`
@@ -255,7 +279,7 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
     },
 
     get(member) {
-      const { classRef, privateNamesMap, file } = this;
+      const { classRef, privateNamesMap, file, innerBinding } = this;
       const { name } = (member.node.property as t.PrivateName).id;
       const {
         id,
@@ -273,6 +297,10 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
             ? "classStaticPrivateMethodGet"
             : "classStaticPrivateFieldSpecGet";
 
+        // if there are any local variable shadowing classRef, unshadow it
+        // see #12960
+        unshadow(classRef.name, member.scope, innerBinding);
+
         return t.callExpression(file.addHelper(helperName), [
           this.receiver(member),
           t.cloneNode(classRef),
@@ -463,8 +491,8 @@ export function transformPrivateNamesUsage(
   ref: t.Identifier,
   path: NodePath<t.Class>,
   privateNamesMap: PrivateNamesMap,
-  { privateFieldsAsProperties, noDocumentAll },
-  state,
+  { privateFieldsAsProperties, noDocumentAll, innerBinding },
+  state: File,
 ) {
   if (!privateNamesMap.size) return;
 
@@ -479,12 +507,14 @@ export function transformPrivateNamesUsage(
     file: state,
     ...handler,
     noDocumentAll,
+    innerBinding,
   });
   body.traverse(privateInVisitor, {
     privateNamesMap,
     classRef: ref,
     file: state,
     privateFieldsAsProperties,
+    innerBinding,
   });
 }
 
@@ -510,16 +540,31 @@ function buildPrivateInstanceFieldInitSpec(
   ref: t.Expression,
   prop: NodePath<t.ClassPrivateProperty>,
   privateNamesMap: PrivateNamesMap,
+  state,
 ) {
   const { id } = privateNamesMap.get(prop.node.key.id.name);
   const value = prop.node.value || prop.scope.buildUndefinedNode();
 
-  return template.statement.ast`${t.cloneNode(id)}.set(${ref}, {
-    // configurable is always false for private elements
-    // enumerable is always false for private elements
-    writable: true,
-    value: ${value},
-  })`;
+  if (!process.env.BABEL_8_BREAKING) {
+    if (!state.availableHelper("classPrivateFieldInitSpec")) {
+      return template.statement.ast`${t.cloneNode(id)}.set(${ref}, {
+        // configurable is always false for private elements
+        // enumerable is always false for private elements
+        writable: true,
+        value: ${value},
+      })`;
+    }
+  }
+
+  const helper = state.addHelper("classPrivateFieldInitSpec");
+  return template.statement.ast`${helper}(
+    ${t.thisExpression()},
+    ${t.cloneNode(id)},
+    {
+      writable: true,
+      value: ${value}
+    },
+  )`;
 }
 
 function buildPrivateStaticFieldInitSpec(
@@ -602,27 +647,87 @@ function buildPrivateInstanceMethodInitSpec(
   ref: t.Expression,
   prop: NodePath<t.ClassPrivateMethod>,
   privateNamesMap: PrivateNamesMap,
+  state,
 ) {
   const privateName = privateNamesMap.get(prop.node.key.id.name);
-  const { id, getId, setId, initAdded } = privateName;
+  const { getId, setId, initAdded } = privateName;
 
   if (initAdded) return;
 
   const isAccessor = getId || setId;
   if (isAccessor) {
-    privateNamesMap.set(prop.node.key.id.name, {
-      ...privateName,
-      initAdded: true,
-    });
+    return buildPrivateAccessorInitialization(
+      ref,
+      prop,
+      privateNamesMap,
+      state,
+    );
+  }
 
-    return template.statement.ast`
+  return buildPrivateInstanceMethodInitalization(
+    ref,
+    prop,
+    privateNamesMap,
+    state,
+  );
+}
+
+function buildPrivateAccessorInitialization(
+  ref: t.Expression,
+  prop: NodePath<t.ClassPrivateMethod>,
+  privateNamesMap: PrivateNamesMap,
+  state,
+) {
+  const privateName = privateNamesMap.get(prop.node.key.id.name);
+  const { id, getId, setId } = privateName;
+
+  privateNamesMap.set(prop.node.key.id.name, {
+    ...privateName,
+    initAdded: true,
+  });
+
+  if (!process.env.BABEL_8_BREAKING) {
+    if (!state.availableHelper("classPrivateFieldInitSpec")) {
+      return template.statement.ast`
       ${id}.set(${ref}, {
         get: ${getId ? getId.name : prop.scope.buildUndefinedNode()},
         set: ${setId ? setId.name : prop.scope.buildUndefinedNode()}
       });
     `;
+    }
   }
-  return template.statement.ast`${id}.add(${ref})`;
+
+  const helper = state.addHelper("classPrivateFieldInitSpec");
+  return template.statement.ast`${helper}(
+    ${t.thisExpression()},
+    ${t.cloneNode(id)},
+    {
+      get: ${getId ? getId.name : prop.scope.buildUndefinedNode()},
+      set: ${setId ? setId.name : prop.scope.buildUndefinedNode()}
+    },
+  )`;
+}
+
+function buildPrivateInstanceMethodInitalization(
+  ref: t.Expression,
+  prop: NodePath<t.ClassPrivateMethod>,
+  privateNamesMap: PrivateNamesMap,
+  state,
+) {
+  const privateName = privateNamesMap.get(prop.node.key.id.name);
+  const { id } = privateName;
+
+  if (!process.env.BABEL_8_BREAKING) {
+    if (!state.availableHelper("classPrivateMethodInitSpec")) {
+      return template.statement.ast`${id}.add(${ref})`;
+    }
+  }
+
+  const helper = state.addHelper("classPrivateMethodInitSpec");
+  return template.statement.ast`${helper}(
+    ${t.thisExpression()},
+    ${t.cloneNode(id)}
+  )`;
 }
 
 function buildPublicFieldInitLoose(
@@ -770,7 +875,7 @@ const thisContextVisitor = traverse.visitors.merge([
 ]);
 
 const innerReferencesVisitor = {
-  ReferencedIdentifier(path, state) {
+  ReferencedIdentifier(path: NodePath<t.Identifier>, state) {
     if (
       path.scope.bindingIdentifierEquals(path.node.name, state.innerBinding)
     ) {
@@ -831,7 +936,7 @@ export function buildFieldsInitNodes(
   superRef: t.Expression | undefined,
   props: PropPath[],
   privateNamesMap: PrivateNamesMap,
-  state,
+  state: File,
   setPublicClassFields: boolean,
   privateFieldsAsProperties: boolean,
   constantSuper: boolean,
@@ -927,6 +1032,7 @@ export function buildFieldsInitNodes(
             // @ts-expect-error checked in switch
             prop,
             privateNamesMap,
+            state,
           ),
         );
         break;
@@ -955,6 +1061,7 @@ export function buildFieldsInitNodes(
             // @ts-expect-error checked in switch
             prop,
             privateNamesMap,
+            state,
           ),
         );
         pureStaticNodes.push(
diff --git a/packages/babel-helper-create-class-features-plugin/src/index.ts b/packages/babel-helper-create-class-features-plugin/src/index.ts
index 24546834a122..57c7595a158d 100644
--- a/packages/babel-helper-create-class-features-plugin/src/index.ts
+++ b/packages/babel-helper-create-class-features-plugin/src/index.ts
@@ -1,4 +1,5 @@
 import { types as t } from "@babel/core";
+import type { File } from "@babel/core";
 import type { NodePath } from "@babel/traverse";
 import nameFunction from "@babel/helper-function-name";
 import splitExportDeclaration from "@babel/helper-split-export-declaration";
@@ -92,7 +93,7 @@ export function createClassFeaturePlugin({
     },
 
     visitor: {
-      Class(path: NodePath<t.Class>, state) {
+      Class(path: NodePath<t.Class>, state: File) {
         if (this.file.get(versionKey) !== version) return;
 
         verifyUsedFeatures(path, this.file);
@@ -198,6 +199,7 @@ export function createClassFeaturePlugin({
           {
             privateFieldsAsProperties: privateFieldsAsProperties ?? loose,
             noDocumentAll,
+            innerBinding,
           },
           state,
         );
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/input.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/input.js
new file mode 100644
index 000000000000..8bc707067391
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/input.js
@@ -0,0 +1,19 @@
+class Base {
+  constructor(obj) {
+    return obj;
+  }
+}
+
+class Derived extends Base {
+  get #foo() {
+    return 'bar';
+  }
+
+  set #foo(value) {
+    this.#foo = value;
+  }
+
+  static get(obj) {
+    return obj.#foo();
+  }
+}
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/options.json b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/options.json
new file mode 100644
index 000000000000..608f30af0eb3
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/options.json
@@ -0,0 +1,6 @@
+{
+  "presets": [["env", { "shippedProposals": true }]],
+  "targets": {
+    "chrome": "75"
+  }
+}
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/output.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/output.js
new file mode 100644
index 000000000000..f1710074613f
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-accessor/output.js
@@ -0,0 +1,31 @@
+class Base {
+  constructor(obj) {
+    return obj;
+  }
+
+}
+
+var _foo = /*#__PURE__*/new WeakMap();
+
+class Derived extends Base {
+  constructor(...args) {
+    super(...args);
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
+      get: _get_foo,
+      set: _set_foo
+    });
+  }
+
+  static get(obj) {
+    return babelHelpers.classPrivateFieldGet(obj, _foo).call(obj);
+  }
+
+}
+
+function _get_foo() {
+  return 'bar';
+}
+
+function _set_foo(value) {
+  babelHelpers.classPrivateFieldSet(this, _foo, value);
+}
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/input.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/input.js
new file mode 100644
index 000000000000..902695e4e932
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/input.js
@@ -0,0 +1,13 @@
+class Base {
+  constructor(obj) {
+    return obj;
+  }
+}
+
+let counter = 0;
+class Derived extends Base {
+  #foo = ++counter;
+  static get(obj) {
+    return obj.#foo;
+  }
+}
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/options.json b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/options.json
new file mode 100644
index 000000000000..608f30af0eb3
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/options.json
@@ -0,0 +1,6 @@
+{
+  "presets": [["env", { "shippedProposals": true }]],
+  "targets": {
+    "chrome": "75"
+  }
+}
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/output.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/output.js
new file mode 100644
index 000000000000..59fe05cc06db
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-field/output.js
@@ -0,0 +1,25 @@
+class Base {
+  constructor(obj) {
+    return obj;
+  }
+
+}
+
+let counter = 0;
+
+var _foo = /*#__PURE__*/new WeakMap();
+
+class Derived extends Base {
+  constructor(...args) {
+    super(...args);
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
+      writable: true,
+      value: ++counter
+    });
+  }
+
+  static get(obj) {
+    return babelHelpers.classPrivateFieldGet(obj, _foo);
+  }
+
+}
\ No newline at end of file
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/input.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/input.js
new file mode 100644
index 000000000000..1d6529040694
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/input.js
@@ -0,0 +1,15 @@
+class Base {
+  constructor(obj) {
+    return obj;
+  }
+}
+
+class Derived extends Base {
+  #foo() {
+    return 'bar';
+  }
+
+  static get(obj) {
+    return obj.#foo();
+  }
+}
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/options.json b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/options.json
new file mode 100644
index 000000000000..608f30af0eb3
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/options.json
@@ -0,0 +1,6 @@
+{
+  "presets": [["env", { "shippedProposals": true }]],
+  "targets": {
+    "chrome": "75"
+  }
+}
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/output.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/output.js
new file mode 100644
index 000000000000..f5dd07cc5ed5
--- /dev/null
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/field-reinitialization/private-method/output.js
@@ -0,0 +1,24 @@
+class Base {
+  constructor(obj) {
+    return obj;
+  }
+
+}
+
+var _foo = /*#__PURE__*/new WeakSet();
+
+class Derived extends Base {
+  constructor(...args) {
+    super(...args);
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
+  }
+
+  static get(obj) {
+    return babelHelpers.classPrivateMethodGet(obj, _foo, _foo2).call(obj);
+  }
+
+}
+
+function _foo2() {
+  return 'bar';
+}
\ No newline at end of file
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/missing-class-static-blocks-plugin/basic/options.json b/packages/babel-helper-create-class-features-plugin/test/fixtures/missing-class-static-blocks-plugin/basic/options.json
index 04ef00ef4b69..3f0630235cee 100644
--- a/packages/babel-helper-create-class-features-plugin/test/fixtures/missing-class-static-blocks-plugin/basic/options.json
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/missing-class-static-blocks-plugin/basic/options.json
@@ -1,4 +1,7 @@
 {
-  "plugins": ["proposal-class-properties", "syntax-class-static-block"],
+  "plugins": [
+    "proposal-class-properties",
+    "@babel/plugin-syntax-class-static-block"
+  ],
   "throws": "Static class blocks are not enabled. Please add `@babel/plugin-proposal-class-static-block` to your configuration."
 }
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/plugin-proposal-private-methods/loose-false/output.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/plugin-proposal-private-methods/loose-false/output.js
index 6e921bc9e05b..c74df0f555e0 100644
--- a/packages/babel-helper-create-class-features-plugin/test/fixtures/plugin-proposal-private-methods/loose-false/output.js
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/plugin-proposal-private-methods/loose-false/output.js
@@ -2,7 +2,7 @@ var _privateMethod = /*#__PURE__*/new WeakSet();
 
 class X {
   constructor() {
-    _privateMethod.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _privateMethod);
   }
 
 }
diff --git a/packages/babel-helper-create-class-features-plugin/test/fixtures/replace-supers/method/output.js b/packages/babel-helper-create-class-features-plugin/test/fixtures/replace-supers/method/output.js
index af58f2d3c9a8..07429bb7b2d2 100644
--- a/packages/babel-helper-create-class-features-plugin/test/fixtures/replace-supers/method/output.js
+++ b/packages/babel-helper-create-class-features-plugin/test/fixtures/replace-supers/method/output.js
@@ -3,8 +3,7 @@ var _foo = /*#__PURE__*/new WeakSet();
 class A extends B {
   constructor(...args) {
     super(...args);
-
-    _foo.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
   }
 
 }
diff --git a/packages/babel-helpers/src/helpers.ts b/packages/babel-helpers/src/helpers.ts
index 7385e63a714d..0911aee76651 100644
--- a/packages/babel-helpers/src/helpers.ts
+++ b/packages/babel-helpers/src/helpers.ts
@@ -2022,6 +2022,32 @@ helpers.classPrivateMethodGet = helper("7.1.6")`
   }
 `;
 
+helpers.checkPrivateRedeclaration = helper("7.14.1")`
+  export default function _checkPrivateRedeclaration(obj, privateCollection) {
+    if (privateCollection.has(obj)) {
+      throw new TypeError("Cannot initialize the same private elements twice on an object");
+    }
+  }
+`;
+
+helpers.classPrivateFieldInitSpec = helper("7.14.1")`
+  import checkPrivateRedeclaration from "checkPrivateRedeclaration";
+
+  export default function _classPrivateFieldInitSpec(obj, privateMap, value) {
+    checkPrivateRedeclaration(obj, privateMap);
+    privateMap.set(obj, value);
+  }
+`;
+
+helpers.classPrivateMethodInitSpec = helper("7.14.1")`
+  import checkPrivateRedeclaration from "checkPrivateRedeclaration";
+
+  export default function _classPrivateMethodInitSpec(obj, privateSet) {
+    checkPrivateRedeclaration(obj, privateSet);
+    privateSet.add(obj);
+  }
+`;
+
 if (!process.env.BABEL_8_BREAKING) {
   // Use readOnlyError instead
   helpers.classPrivateMethodSet = helper("7.1.6")`
diff --git a/packages/babel-parser/test/fixtures/experimental/_no-plugin/module-blocks/input.js b/packages/babel-parser/test/fixtures/experimental/_no-plugin/module-blocks/input.js
new file mode 100644
index 000000000000..5cf4a422ebf1
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/experimental/_no-plugin/module-blocks/input.js
@@ -0,0 +1,4 @@
+let moduleBlock = module {
+  export let y = 1;
+};
+let moduleExports = await import(moduleBlock);
diff --git a/packages/babel-parser/test/fixtures/experimental/_no-plugin/module-blocks/options.json b/packages/babel-parser/test/fixtures/experimental/_no-plugin/module-blocks/options.json
new file mode 100644
index 000000000000..45ff422e6d5a
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/experimental/_no-plugin/module-blocks/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "This experimental syntax requires enabling the parser plugin: 'moduleBlocks' (1:18)"
+}
\ No newline at end of file
diff --git a/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration-optional-chaining/output.mjs b/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration-optional-chaining/output.mjs
index b9c029038b14..982de805006b 100644
--- a/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration-optional-chaining/output.mjs
+++ b/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration-optional-chaining/output.mjs
@@ -4,11 +4,10 @@ class C {
   constructor() {
     var _babelHelpers$classPr;
 
-    _m.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _m, {
       writable: true,
       value: void 0
     });
-
     const o = null;
     const n = this;
     const p = o === null || o === void 0 ? void 0 : babelHelpers.classPrivateFieldGet(o, _m).call(o, ...c, 1);
diff --git a/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration/output.mjs b/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration/output.mjs
index b9c029038b14..982de805006b 100644
--- a/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration/output.mjs
+++ b/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/fixtures/basic/class-private-integration/output.mjs
@@ -4,11 +4,10 @@ class C {
   constructor() {
     var _babelHelpers$classPr;
 
-    _m.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _m, {
       writable: true,
       value: void 0
     });
-
     const o = null;
     const n = this;
     const p = o === null || o === void 0 ? void 0 : babelHelpers.classPrivateFieldGet(o, _m).call(o, ...c, 1);
diff --git a/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/util.test.js b/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/util.test.js
index 52f4008fcf08..c6937fcc798e 100644
--- a/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/util.test.js
+++ b/packages/babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining/test/util.test.js
@@ -15,6 +15,7 @@ function getPath(input, parserOpts = {}) {
         ...parserOpts,
       },
       filename: "example.js",
+      configFile: false,
     }),
     {
       "OptionalMemberExpression|OptionalCallExpression"(path) {
diff --git a/packages/babel-plugin-proposal-async-generator-functions/test/fixtures/async-generators/class-private-method/output.js b/packages/babel-plugin-proposal-async-generator-functions/test/fixtures/async-generators/class-private-method/output.js
index edaf639ec2f7..92c4e90b13c8 100644
--- a/packages/babel-plugin-proposal-async-generator-functions/test/fixtures/async-generators/class-private-method/output.js
+++ b/packages/babel-plugin-proposal-async-generator-functions/test/fixtures/async-generators/class-private-method/output.js
@@ -2,7 +2,7 @@ var _g = /*#__PURE__*/new WeakSet();
 
 class C {
   constructor() {
-    _g.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _g);
   }
 
 }
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/exec.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/exec.js
new file mode 100644
index 000000000000..101547f13cee
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/exec.js
@@ -0,0 +1,15 @@
+class Test {
+
+  static #x = 1
+
+  static method() {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return this.#x + Test;
+    }
+    return func() + Test;
+  }
+}
+
+expect(Test.method()).toBe(6)
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/input.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/input.js
new file mode 100644
index 000000000000..5f5ffa0b2343
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/input.js
@@ -0,0 +1,13 @@
+class Test {
+
+  static #x = 1
+
+  static method() {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return this.#x + Test;
+    }
+    return func() + Test;
+  }
+}
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/options.json b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/options.json
new file mode 100644
index 000000000000..19ed5174f545
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-properties"]
+}
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/output.js
new file mode 100644
index 000000000000..8b03caa83f92
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private-loose/static-shadow/output.js
@@ -0,0 +1,18 @@
+class Test {
+  static method() {
+    const _Test2 = 2;
+
+    const func = () => {
+      const _Test = 3;
+      return babelHelpers.classStaticPrivateFieldSpecGet(this, Test, _x) + _Test;
+    };
+
+    return func() + _Test2;
+  }
+
+}
+
+var _x = {
+  writable: true,
+  value: 1
+};
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/1-helpermemberexpressionfunction/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/1-helpermemberexpressionfunction/output.js
index 89ad20142e0e..ff85bfa4598f 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/1-helpermemberexpressionfunction/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/1-helpermemberexpressionfunction/output.js
@@ -5,8 +5,7 @@ var D = /*#__PURE__*/function () {
 
   function D() {
     babelHelpers.classCallCheck(this, D);
-
-    _arr.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _arr, {
       writable: true,
       value: void 0
     });
@@ -30,8 +29,7 @@ var C = /*#__PURE__*/function () {
 
   function C() {
     babelHelpers.classCallCheck(this, C);
-
-    _p.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _p, {
       writable: true,
       value: void 0
     });
@@ -55,8 +53,7 @@ var E = /*#__PURE__*/function () {
 
   function E() {
     babelHelpers.classCallCheck(this, E);
-
-    _arr2.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _arr2, {
       writable: true,
       value: void 0
     });
@@ -80,8 +77,7 @@ var F = /*#__PURE__*/function () {
 
   function F() {
     babelHelpers.classCallCheck(this, F);
-
-    _ar.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _ar, {
       writable: true,
       value: void 0
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/assignment/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/assignment/output.js
index a7817db0ff01..e0c46183b855 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/assignment/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/assignment/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 0
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/call/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/call/output.js
index 27947d1df63f..2b12c7ae9bac 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/call/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/call/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: function () {
         return this;
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/canonical/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/canonical/output.js
index e41035c44796..5fc50758bc10 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/canonical/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/canonical/output.js
@@ -7,17 +7,14 @@ var Point = /*#__PURE__*/function () {
 
   function Point(x = 0, y = 0) {
     babelHelpers.classCallCheck(this, Point);
-
-    _x.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _x, {
       writable: true,
       value: void 0
     });
-
-    _y.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _y, {
       writable: true,
       value: void 0
     });
-
     babelHelpers.classPrivateFieldSet(this, _x, +x);
     babelHelpers.classPrivateFieldSet(this, _y, +y);
   }
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/constructor-collision/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/constructor-collision/output.js
index 05d01f4911b9..134fb98bdedf 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/constructor-collision/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/constructor-collision/output.js
@@ -6,11 +6,9 @@ var Foo = function Foo() {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _bar.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _bar, {
     writable: true,
     value: foo
   });
-
   var _foo = "foo";
 };
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/declaration-order/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/declaration-order/output.js
index b2c777ecc3ef..f3620fbdc887 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/declaration-order/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/declaration-order/output.js
@@ -5,8 +5,7 @@ var C = function C() {
 
   babelHelpers.classCallCheck(this, C);
   babelHelpers.defineProperty(this, "y", babelHelpers.classPrivateFieldGet(this, _x));
-
-  _x.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _x, {
     writable: true,
     value: void 0
   });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived-multiple-supers/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived-multiple-supers/output.js
index 06197e31d481..692b0bf2c253 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived-multiple-supers/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived-multiple-supers/output.js
@@ -14,15 +14,13 @@ var Foo = /*#__PURE__*/function (_Bar) {
 
     if (condition) {
       _this = _super.call(this);
-
-      _bar.set(babelHelpers.assertThisInitialized(_this), {
+      babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _bar, {
         writable: true,
         value: "foo"
       });
     } else {
       _this = _super.call(this);
-
-      _bar.set(babelHelpers.assertThisInitialized(_this), {
+      babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _bar, {
         writable: true,
         value: "foo"
       });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived/output.js
index 97251962ae41..d21589418236 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/derived/output.js
@@ -4,8 +4,7 @@ var Foo = function Foo() {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _prop.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _prop, {
     writable: true,
     value: "foo"
   });
@@ -25,12 +24,10 @@ var Bar = /*#__PURE__*/function (_Foo) {
 
     babelHelpers.classCallCheck(this, Bar);
     _this = _super.call(this, ...args);
-
-    _prop2.set(babelHelpers.assertThisInitialized(_this), {
+    babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _prop2, {
       writable: true,
       value: "bar"
     });
-
     return _this;
   }
 
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-1/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-1/output.js
index 1b13a2e595c3..f8813d3f0212 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-1/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-1/output.js
@@ -4,12 +4,10 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   babelHelpers.classPrivateFieldSet(this, _client, 1);
   [this.x = babelHelpers.classPrivateFieldGet(this, _client), babelHelpers.classPrivateFieldDestructureSet(this, _client).value, this.y = babelHelpers.classPrivateFieldGet(this, _client)] = props;
 };
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-2/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-2/output.js
index 2ace67a331c0..9f88740d8363 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-2/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-2/output.js
@@ -4,11 +4,9 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   [x, ...babelHelpers.classPrivateFieldDestructureSet(this, _client).value] = props;
 };
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-3/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-3/output.js
index 6b9882ec1bc7..091bdecc0da9 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-3/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern-3/output.js
@@ -4,11 +4,9 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   [babelHelpers.classPrivateFieldDestructureSet(this, _client).value = 5] = props;
 };
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern/output.js
index ffeb7c001e44..eeae89405a83 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-array-pattern/output.js
@@ -4,11 +4,9 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   [babelHelpers.classPrivateFieldDestructureSet(this, _client).value] = props;
 };
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-1/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-1/output.js
index bb48cc08e11b..2522895f077e 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-1/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-1/output.js
@@ -4,12 +4,10 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   babelHelpers.classPrivateFieldSet(this, _client, 'foo');
   ({
     x: this.x = babelHelpers.classPrivateFieldGet(this, _client),
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-2/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-2/output.js
index 1ffd2fe58ffa..94f7111188c4 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-2/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-2/output.js
@@ -4,12 +4,10 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   ({
     x,
     ...babelHelpers.classPrivateFieldDestructureSet(this, _client).value
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-3/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-3/output.js
index 0c4192589582..071bae2f50d7 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-3/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern-3/output.js
@@ -4,12 +4,10 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   ({
     x: babelHelpers.classPrivateFieldDestructureSet(this, _client).value = 5
   } = props);
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern/output.js
index 7459b76bc979..6366d6e7f5a5 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/destructuring-object-pattern/output.js
@@ -4,12 +4,10 @@ var Foo = function Foo(props) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _client.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _client, {
     writable: true,
     value: void 0
   });
-
   ({
     client: babelHelpers.classPrivateFieldDestructureSet(this, _client).value
   } = props);
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/extracted-this/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/extracted-this/output.js
index 1fb7de2ab41d..5bbb120d1a6a 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/extracted-this/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/extracted-this/output.js
@@ -8,13 +8,11 @@ var Foo = function Foo(_foo) {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _bar.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _bar, {
     writable: true,
     value: this
   });
-
-  _baz.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _baz, {
     writable: true,
     value: foo
   });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/foobar/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/foobar/output.js
index 2ae9b573b32d..496503850a30 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/foobar/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/foobar/output.js
@@ -12,14 +12,12 @@ var Child = /*#__PURE__*/function (_Parent) {
 
     babelHelpers.classCallCheck(this, Child);
     _this = _super.call(this);
-
-    _scopedFunctionWithThis.set(babelHelpers.assertThisInitialized(_this), {
+    babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _scopedFunctionWithThis, {
       writable: true,
       value: () => {
         _this.name = {};
       }
     });
-
     return _this;
   }
 
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance-undefined/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance-undefined/output.js
index 8c8ba57dec55..dfa75cf39d8c 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance-undefined/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance-undefined/output.js
@@ -4,8 +4,7 @@ var Foo = function Foo() {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _bar.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _bar, {
     writable: true,
     value: void 0
   });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance/output.js
index c7208f4d74b2..c30d93994e22 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/instance/output.js
@@ -4,8 +4,7 @@ var Foo = function Foo() {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _bar.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _bar, {
     writable: true,
     value: "foo"
   });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/logical-assignment/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/logical-assignment/output.js
index e61da807cef9..012356bcec0c 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/logical-assignment/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/logical-assignment/output.js
@@ -6,17 +6,15 @@ var _or = /*#__PURE__*/new WeakMap();
 
 class Foo {
   constructor() {
-    _nullish.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _nullish, {
       writable: true,
       value: 0
     });
-
-    _and.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _and, {
       writable: true,
       value: 0
     });
-
-    _or.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _or, {
       writable: true,
       value: 0
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/multiple/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/multiple/output.js
index fd609d445893..de23ee50d176 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/multiple/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/multiple/output.js
@@ -6,13 +6,11 @@ var Foo = function Foo() {
   "use strict";
 
   babelHelpers.classCallCheck(this, Foo);
-
-  _x.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _x, {
     writable: true,
     value: 0
   });
-
-  _y.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _y, {
     writable: true,
     value: babelHelpers.classPrivateFieldGet(this, _x)
   });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/native-classes/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/native-classes/output.js
index 98f497349993..cca3df0b1e97 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/native-classes/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/native-classes/output.js
@@ -2,7 +2,7 @@ var _bar = /*#__PURE__*/new WeakMap();
 
 class Foo {
   constructor() {
-    _bar.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _bar, {
       writable: true,
       value: "bar"
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed-redeclared/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed-redeclared/output.js
index 1dd4c23b4a31..1f1a88576bf3 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed-redeclared/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed-redeclared/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
@@ -24,8 +23,7 @@ var Foo = /*#__PURE__*/function () {
       var Nested = /*#__PURE__*/function (_babelHelpers$classPr2) {
         function Nested() {
           babelHelpers.classCallCheck(this, Nested);
-
-          _foo2.set(this, {
+          babelHelpers.classPrivateFieldInitSpec(this, _foo2, {
             writable: true,
             value: 2
           });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed/output.js
index e5d21a94663d..73762088ae78 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-computed/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed-redeclared/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed-redeclared/output.js
index 816f80cbeb00..05370b34fc85 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed-redeclared/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed-redeclared/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
@@ -31,12 +30,10 @@ var Foo = /*#__PURE__*/function () {
 
           babelHelpers.classCallCheck(this, Nested);
           _this = _super.call(this, ...args);
-
-          _foo2.set(babelHelpers.assertThisInitialized(_this), {
+          babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _foo2, {
             writable: true,
             value: 3
           });
-
           return _this;
         }
 
@@ -44,12 +41,10 @@ var Foo = /*#__PURE__*/function () {
       }((_foo3 = /*#__PURE__*/new WeakMap(), _babelHelpers$classPr = babelHelpers.classPrivateFieldGet(this, _foo3), /*#__PURE__*/function () {
         function _class2() {
           babelHelpers.classCallCheck(this, _class2);
-
-          _foo3.set(this, {
+          babelHelpers.classPrivateFieldInitSpec(this, _foo3, {
             writable: true,
             value: 2
           });
-
           babelHelpers.defineProperty(this, _babelHelpers$classPr, 2);
         }
 
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed/output.js
index dddde36ed4d4..378e354e71d6 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-extends-computed/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
@@ -29,12 +28,10 @@ var Foo = /*#__PURE__*/function () {
 
           babelHelpers.classCallCheck(this, Nested);
           _this = _super.call(this, ...args);
-
-          _foo2.set(babelHelpers.assertThisInitialized(_this), {
+          babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _foo2, {
             writable: true,
             value: 3
           });
-
           return _this;
         }
 
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-other-redeclared/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-other-redeclared/output.js
index 080795751a9a..134b4cab21c9 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-other-redeclared/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-other-redeclared/output.js
@@ -7,13 +7,11 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
-
-    _bar.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _bar, {
       writable: true,
       value: 1
     });
@@ -27,8 +25,7 @@ var Foo = /*#__PURE__*/function () {
       var Nested = /*#__PURE__*/function () {
         function Nested() {
           babelHelpers.classCallCheck(this, Nested);
-
-          _bar2.set(this, {
+          babelHelpers.classPrivateFieldInitSpec(this, _bar2, {
             writable: true,
             value: 2
           });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-redeclared/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-redeclared/output.js
index 1030037c7a75..a507af4249b1 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-redeclared/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class-redeclared/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
@@ -20,8 +19,7 @@ var Foo = /*#__PURE__*/function () {
       var Nested = /*#__PURE__*/function () {
         function Nested() {
           babelHelpers.classCallCheck(this, Nested);
-
-          _foo2.set(this, {
+          babelHelpers.classPrivateFieldInitSpec(this, _foo2, {
             writable: true,
             value: 2
           });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class/output.js
index 69123eded43d..df432fc79aa7 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/nested-class/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/optional-chain-member-optional-call-spread-arguments/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/optional-chain-member-optional-call-spread-arguments/output.js
index 593a5772ca7b..58e1533d26df 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/optional-chain-member-optional-call-spread-arguments/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/optional-chain-member-optional-call-spread-arguments/output.js
@@ -2,7 +2,7 @@ var _m = /*#__PURE__*/new WeakMap();
 
 class Foo {
   constructor() {
-    _m.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _m, {
       writable: true,
       value: void 0
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/private-in-derived/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/private-in-derived/output.js
index 1e5799660027..f2c1dbcfb016 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/private-in-derived/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/private-in-derived/output.js
@@ -4,8 +4,7 @@ var Outer = function Outer() {
   "use strict";
 
   babelHelpers.classCallCheck(this, Outer);
-
-  _outer.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _outer, {
     writable: true,
     value: void 0
   });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reevaluated/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reevaluated/output.js
index 8c6a9554122f..6c22c5c9bf08 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reevaluated/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reevaluated/output.js
@@ -3,7 +3,7 @@ function classFactory() {
 
   return _temp = (_foo = /*#__PURE__*/new WeakMap(), _class = class Foo {
     constructor() {
-      _foo.set(this, {
+      babelHelpers.classPrivateFieldInitSpec(this, _foo, {
         writable: true,
         value: "foo"
       });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reference-in-other-property/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reference-in-other-property/output.js
index 0b7476ce49a0..6c3d52803c44 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reference-in-other-property/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/reference-in-other-property/output.js
@@ -9,20 +9,16 @@ var Foo = function Foo() {
 
   babelHelpers.classCallCheck(this, Foo);
   babelHelpers.defineProperty(this, "one", babelHelpers.classPrivateFieldGet(this, _private));
-
-  _two.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _two, {
     writable: true,
     value: babelHelpers.classPrivateFieldGet(this, _private)
   });
-
-  _private.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _private, {
     writable: true,
     value: 0
   });
-
   babelHelpers.defineProperty(this, "three", babelHelpers.classPrivateFieldGet(this, _private));
-
-  _four.set(this, {
+  babelHelpers.classPrivateFieldInitSpec(this, _four, {
     writable: true,
     value: babelHelpers.classPrivateFieldGet(this, _private)
   });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/regression-T7364/output.mjs b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/regression-T7364/output.mjs
index ae07dabb7896..7d23ce353bbc 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/regression-T7364/output.mjs
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/regression-T7364/output.mjs
@@ -4,7 +4,7 @@ class MyClass {
   constructor() {
     var _this = this;
 
-    _myAsyncMethod.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _myAsyncMethod, {
       writable: true,
       value: function () {
         var _ref = babelHelpers.asyncToGenerator(function* () {
@@ -26,7 +26,7 @@ var _myAsyncMethod2 = /*#__PURE__*/new WeakMap();
   constructor() {
     var _this2 = this;
 
-    _myAsyncMethod2.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _myAsyncMethod2, {
       writable: true,
       value: function () {
         var _ref2 = babelHelpers.asyncToGenerator(function* () {
@@ -48,7 +48,7 @@ export default class MyClass3 {
   constructor() {
     var _this3 = this;
 
-    _myAsyncMethod3.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _myAsyncMethod3, {
       writable: true,
       value: function () {
         var _ref3 = babelHelpers.asyncToGenerator(function* () {
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/exec.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/exec.js
new file mode 100644
index 000000000000..101547f13cee
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/exec.js
@@ -0,0 +1,15 @@
+class Test {
+
+  static #x = 1
+
+  static method() {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return this.#x + Test;
+    }
+    return func() + Test;
+  }
+}
+
+expect(Test.method()).toBe(6)
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/input.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/input.js
new file mode 100644
index 000000000000..5f5ffa0b2343
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/input.js
@@ -0,0 +1,13 @@
+class Test {
+
+  static #x = 1
+
+  static method() {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return this.#x + Test;
+    }
+    return func() + Test;
+  }
+}
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/options.json b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/options.json
new file mode 100644
index 000000000000..19ed5174f545
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-properties"]
+}
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/output.js
new file mode 100644
index 000000000000..8b03caa83f92
--- /dev/null
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/static-shadow/output.js
@@ -0,0 +1,18 @@
+class Test {
+  static method() {
+    const _Test2 = 2;
+
+    const func = () => {
+      const _Test = 3;
+      return babelHelpers.classStaticPrivateFieldSpecGet(this, Test, _x) + _Test;
+    };
+
+    return func() + _Test2;
+  }
+
+}
+
+var _x = {
+  writable: true,
+  value: 1
+};
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-call/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-call/output.js
index 78bcdf3764a0..c329d248e38c 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-call/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-call/output.js
@@ -28,12 +28,10 @@ var B = /*#__PURE__*/function (_A) {
 
     babelHelpers.classCallCheck(this, B);
     _this = _super.call(this, ...args);
-
-    _foo.set(babelHelpers.assertThisInitialized(_this), {
+    babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _foo, {
       writable: true,
       value: babelHelpers.get((_thisSuper = babelHelpers.assertThisInitialized(_this), babelHelpers.getPrototypeOf(B.prototype)), "foo", _thisSuper).call(_thisSuper)
     });
-
     return _this;
   }
 
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-expression/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-expression/output.js
index 1f17e973a223..d3b2bb1e9ed1 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-expression/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-expression/output.js
@@ -11,7 +11,7 @@ var Foo = /*#__PURE__*/function (_Bar) {
     var _temp, _this;
 
     babelHelpers.classCallCheck(this, Foo);
-    foo((_temp = _this = _super.call(this), _bar.set(babelHelpers.assertThisInitialized(_this), {
+    foo((_temp = _this = _super.call(this), babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _bar, {
       writable: true,
       value: "foo"
     }), _temp));
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-statement/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-statement/output.js
index e652b376af27..310bfc691ca5 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-statement/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/super-statement/output.js
@@ -12,12 +12,10 @@ var Foo = /*#__PURE__*/function (_Bar) {
 
     babelHelpers.classCallCheck(this, Foo);
     _this = _super.call(this);
-
-    _bar.set(babelHelpers.assertThisInitialized(_this), {
+    babelHelpers.classPrivateFieldInitSpec(babelHelpers.assertThisInitialized(_this), _bar, {
       writable: true,
       value: "foo"
     });
-
     return _this;
   }
 
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/tagged-template/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/tagged-template/output.js
index b06497c1fcdc..530024699bfe 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/tagged-template/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/tagged-template/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _tag.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _tag, {
       writable: true,
       value: void 0
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/update/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/update/output.js
index 59d092de2de4..cab004ed47e6 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/private/update/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/private/update/output.js
@@ -5,8 +5,7 @@ var Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 0
     });
diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/output.js
index f41cc8189c3d..fc17c143e229 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/8882/output.js
@@ -8,8 +8,7 @@ for (let i = 0; i <= 10; ++i) {
   classes.push((_temp = (_bar = /*#__PURE__*/new WeakMap(), _i = i, _class = class A {
     constructor() {
       babelHelpers.defineProperty(this, _i, `computed field ${i}`);
-
-      _bar.set(this, {
+      babelHelpers.classPrivateFieldInitSpec(this, _bar, {
         writable: true,
         value: `private field ${i}`
       });
diff --git a/packages/babel-plugin-proposal-class-static-block/package.json b/packages/babel-plugin-proposal-class-static-block/package.json
index 8b41f2cb7d61..341d6c908e69 100644
--- a/packages/babel-plugin-proposal-class-static-block/package.json
+++ b/packages/babel-plugin-proposal-class-static-block/package.json
@@ -21,7 +21,7 @@
   "dependencies": {
     "@babel/helper-create-class-features-plugin": "workspace:^7.14.5",
     "@babel/helper-plugin-utils": "workspace:^7.14.5",
-    "@babel/plugin-syntax-class-static-block": "workspace:^7.14.5"
+    "@babel/plugin-syntax-class-static-block": "^7.14.5"
   },
   "peerDependencies": {
     "@babel/core": "^7.12.0"
diff --git a/packages/babel-plugin-proposal-class-static-block/src/index.js b/packages/babel-plugin-proposal-class-static-block/src/index.js
index 67b2526a8ca4..5bc560fc77cb 100644
--- a/packages/babel-plugin-proposal-class-static-block/src/index.js
+++ b/packages/babel-plugin-proposal-class-static-block/src/index.js
@@ -29,7 +29,7 @@ export default declare(({ types: t, template, assertVersion }) => {
 
   return {
     name: "proposal-class-static-block",
-    inherits: syntaxClassStaticBlock,
+    inherits: syntaxClassStaticBlock.default,
 
     pre() {
       // Enable this in @babel/helper-create-class-features-plugin, so that it
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/basic/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/basic/output.js
index 658554a063b1..4b64a3333d2f 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/basic/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/basic/output.js
@@ -4,16 +4,14 @@ var _privateFieldValue = /*#__PURE__*/new WeakMap();
 
 class Cl {
   constructor() {
-    _privateFieldValue.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateFieldValue, {
       get: _get_privateFieldValue,
       set: _set_privateFieldValue
     });
-
-    _privateField.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateField, {
       writable: true,
       value: "top secret string"
     });
-
     this.publicField = "not secret string";
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/get-only-setter/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/get-only-setter/output.js
index 2a0691beefac..6c95f5f1bbdd 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/get-only-setter/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/get-only-setter/output.js
@@ -4,16 +4,14 @@ var _privateFieldValue = /*#__PURE__*/new WeakMap();
 
 class Cl {
   constructor() {
-    _privateFieldValue.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateFieldValue, {
       get: void 0,
       set: _set_privateFieldValue
     });
-
-    _privateField.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateField, {
       writable: true,
       value: 0
     });
-
     this.publicField = (this, babelHelpers.writeOnlyError("#privateFieldValue"));
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/reassignment/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/reassignment/output.js
index 4ee6f05ac82d..3cd48da10e76 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/reassignment/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/reassignment/output.js
@@ -4,11 +4,10 @@ var _privateFieldValue = /*#__PURE__*/new WeakMap();
 
 class Foo {
   constructor() {
-    _privateFieldValue.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateFieldValue, {
       get: _get_privateFieldValue,
       set: void 0
     });
-
     this.self, results.push(2), babelHelpers.readOnlyError("#privateFieldValue");
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/set-only-getter/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/set-only-getter/output.js
index 52a97f6ec2bd..99848e09ac72 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/set-only-getter/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/set-only-getter/output.js
@@ -9,16 +9,14 @@ class Cl {
   }
 
   constructor() {
-    _privateFieldValue.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateFieldValue, {
       get: _get_privateFieldValue,
       set: void 0
     });
-
-    _privateField.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateField, {
       writable: true,
       value: 0
     });
-
     babelHelpers.defineProperty(this, "counter", 0);
     this.self, 1([babelHelpers.classPrivateFieldDestructureSet(this.self, _privateFieldValue).value] = [1]), babelHelpers.readOnlyError("#privateFieldValue");
   }
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/tagged-template/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/tagged-template/output.js
index 90a909b22bbe..c8b534f929cf 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/tagged-template/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/tagged-template/output.js
@@ -2,11 +2,10 @@ var _tag = /*#__PURE__*/new WeakMap();
 
 class Foo {
   constructor() {
-    _tag.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _tag, {
       get: _get_tag,
       set: void 0
     });
-
     babelHelpers.classPrivateFieldGet(this, _tag).bind(this)``;
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/updates/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/updates/output.js
index 0da9a9fc0775..a3e609e11f35 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/updates/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/accessors/updates/output.js
@@ -4,16 +4,14 @@ var _privateFieldValue = /*#__PURE__*/new WeakMap();
 
 class Cl {
   constructor() {
-    _privateFieldValue.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateFieldValue, {
       get: _get_privateFieldValue,
       set: _set_privateFieldValue
     });
-
-    _privateField.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateField, {
       writable: true,
       value: "top secret string"
     });
-
     this.publicField = "not secret string";
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/assumption-constantSuper/private-method-super/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/assumption-constantSuper/private-method-super/output.js
index 74762cfc049b..b0c6dcfb4a85 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/assumption-constantSuper/private-method-super/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/assumption-constantSuper/private-method-super/output.js
@@ -10,8 +10,7 @@ var _privateMethod = /*#__PURE__*/new WeakSet();
 class Sub extends Base {
   constructor(...args) {
     super(...args);
-
-    _privateMethod.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _privateMethod);
   }
 
   superMethod() {
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/get-set/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/get-set/output.js
index 995151f76286..e4e64c0f3494 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/get-set/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/get-set/output.js
@@ -4,12 +4,11 @@ var _getSet = /*#__PURE__*/new WeakMap();
 
 class Cl {
   constructor() {
-    _getSet.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _getSet, {
       get: _get_getSet,
       set: _set_getSet
     });
-
-    _privateField.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateField, {
       writable: true,
       value: 0
     });
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/set-get/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/set-get/output.js
index 3c26592e7614..10379c8a3700 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/set-get/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/duplicated-names/set-get/output.js
@@ -4,12 +4,11 @@ var _getSet = /*#__PURE__*/new WeakMap();
 
 class Cl {
   constructor() {
-    _getSet.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _getSet, {
       get: _get_getSet,
       set: _set_getSet
     });
-
-    _privateField.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _privateField, {
       writable: true,
       value: 0
     });
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/assignment/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/assignment/output.js
index 0c4c7958abdc..368062ce9a74 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/assignment/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/assignment/output.js
@@ -2,8 +2,7 @@ var _privateMethod = /*#__PURE__*/new WeakSet();
 
 class Foo {
   constructor() {
-    _privateMethod.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _privateMethod);
     this.publicField = babelHelpers.classPrivateMethodGet(this, _privateMethod, _privateMethod2).call(this);
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/async/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/async/output.js
index 256f7fe629c0..13ee286f7c87 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/async/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/async/output.js
@@ -2,7 +2,7 @@ var _foo = /*#__PURE__*/new WeakSet();
 
 class Cl {
   constructor() {
-    _foo.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
   }
 
   test() {
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/before-fields/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/before-fields/output.js
index 447aba2a5082..fe5a04321881 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/before-fields/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/before-fields/output.js
@@ -4,11 +4,9 @@ var _method = /*#__PURE__*/new WeakSet();
 
 class Cl {
   constructor() {
-    _method.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _method);
     babelHelpers.defineProperty(this, "prop", babelHelpers.classPrivateMethodGet(this, _method, _method2).call(this, 1));
-
-    _priv.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _priv, {
       writable: true,
       value: babelHelpers.classPrivateMethodGet(this, _method, _method2).call(this, 2)
     });
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/class-expression/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/class-expression/output.js
index f0c034edfe8c..b177284a7867 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/class-expression/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/class-expression/output.js
@@ -2,7 +2,7 @@ var _foo;
 
 console.log((_foo = /*#__PURE__*/new WeakSet(), class A {
   constructor() {
-    _foo.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
   }
 
   method() {
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/context/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/context/output.js
index 0be6a465b0b9..9d96c81401a5 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/context/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/context/output.js
@@ -2,8 +2,7 @@ var _getStatus = /*#__PURE__*/new WeakSet();
 
 class Foo {
   constructor(status) {
-    _getStatus.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _getStatus);
     this.status = status;
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/exfiltrated/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/exfiltrated/output.js
index 88d1606b8f96..cac29e2bd16f 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/exfiltrated/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/exfiltrated/output.js
@@ -4,7 +4,7 @@ var _privateMethod = /*#__PURE__*/new WeakSet();
 
 class Foo {
   constructor() {
-    _privateMethod.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _privateMethod);
 
     if (exfiltrated === undefined) {
       exfiltrated = babelHelpers.classPrivateMethodGet(this, _privateMethod, _privateMethod2);
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/generator/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/generator/output.js
index 2d3984fd5d5a..565cde34ac84 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/generator/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/generator/output.js
@@ -2,7 +2,7 @@ var _foo = /*#__PURE__*/new WeakSet();
 
 class Cl {
   constructor() {
-    _foo.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
   }
 
   test() {
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/read-only/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/read-only/output.js
index 9b9b5db27968..cf55c305310b 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/read-only/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/read-only/output.js
@@ -7,8 +7,7 @@ class A {
   }
 
   constructor() {
-    _method.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _method);
     babelHelpers.defineProperty(this, "counter", 0);
     this.self(), 2, babelHelpers.readOnlyError("#method");
     [babelHelpers.classPrivateFieldDestructureSet(this, _method).value] = [2];
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/reassignment/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/reassignment/output.js
index d06ddb53ec2b..6fc9d8e6bc40 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/reassignment/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/reassignment/output.js
@@ -4,8 +4,7 @@ var _privateFieldValue = /*#__PURE__*/new WeakSet();
 
 class Foo {
   constructor() {
-    _privateFieldValue.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _privateFieldValue);
     this.self, results.push(2), babelHelpers.readOnlyError("#privateFieldValue");
   }
 
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/super/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/super/output.js
index 475654149f6a..25ba5547ffb6 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/super/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/super/output.js
@@ -10,8 +10,7 @@ var _privateMethod = /*#__PURE__*/new WeakSet();
 class Sub extends Base {
   constructor(...args) {
     super(...args);
-
-    _privateMethod.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _privateMethod);
   }
 
   superMethod() {
diff --git a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/tagged-template/output.js b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/tagged-template/output.js
index 21029095ae9a..fb9580a3f92b 100644
--- a/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/tagged-template/output.js
+++ b/packages/babel-plugin-proposal-private-methods/test/fixtures/private-method/tagged-template/output.js
@@ -2,7 +2,7 @@ var _tag = /*#__PURE__*/new WeakSet();
 
 class Foo {
   constructor() {
-    _tag.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _tag);
   }
 
 }
diff --git a/packages/babel-plugin-proposal-private-property-in-object/package.json b/packages/babel-plugin-proposal-private-property-in-object/package.json
index 499c6fc3da1e..50a538a3682b 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/package.json
+++ b/packages/babel-plugin-proposal-private-property-in-object/package.json
@@ -20,7 +20,7 @@
     "@babel/helper-annotate-as-pure": "workspace:^7.14.5",
     "@babel/helper-create-class-features-plugin": "workspace:^7.14.5",
     "@babel/helper-plugin-utils": "workspace:^7.14.5",
-    "@babel/plugin-syntax-private-property-in-object": "workspace:^7.14.5"
+    "@babel/plugin-syntax-private-property-in-object": "^7.14.5"
   },
   "peerDependencies": {
     "@babel/core": "^7.0.0-0"
diff --git a/packages/babel-plugin-proposal-private-property-in-object/src/index.js b/packages/babel-plugin-proposal-private-property-in-object/src/index.js
index 9d7d31a2942b..094e054c669c 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/src/index.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/src/index.js
@@ -84,7 +84,7 @@ export default declare(({ assertVersion, types: t, template }, { loose }) => {
 
   return {
     name: "proposal-private-property-in-object",
-    inherits: syntaxPlugin,
+    inherits: syntaxPlugin.default,
     pre() {
       // Enable this in @babel/helper-create-class-features-plugin, so that it
       // can be handled by the private fields and methods transform.
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/native-classes/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/native-classes/output.js
index 13ebbe421023..51e66218a8ab 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/native-classes/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/native-classes/output.js
@@ -2,7 +2,7 @@ var _bar = /*#__PURE__*/new WeakMap();
 
 class Foo {
   constructor() {
-    _bar.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _bar, {
       writable: true,
       value: "bar"
     });
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/exec.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/exec.js
new file mode 100644
index 000000000000..673b1cced3af
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/exec.js
@@ -0,0 +1,17 @@
+class Test {
+
+  static #x = 1
+
+  method(other) {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return #x in other && Test;
+    }
+    return func() + Test;
+  }
+}
+
+const t = new Test();
+const t2 = new Test();
+expect(t.method(Test)).toBe(5)
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/input.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/input.js
new file mode 100644
index 000000000000..faa4ce3d104a
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/input.js
@@ -0,0 +1,13 @@
+class Test {
+
+  static #x = 1
+
+  method(other) {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return #x in other && Test;
+    }
+    return func() + Test;
+  }
+}
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/options.json b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/options.json
new file mode 100644
index 000000000000..19ed5174f545
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-properties"]
+}
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/output.js
new file mode 100644
index 000000000000..898d6a8ddcfb
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/static-shadow/output.js
@@ -0,0 +1,18 @@
+class Test {
+  method(other) {
+    const _Test2 = 2;
+
+    const func = () => {
+      const _Test = 3;
+      return other === Test && _Test;
+    };
+
+    return func() + _Test2;
+  }
+
+}
+
+var _x = {
+  writable: true,
+  value: 1
+};
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/accessor/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/accessor/output.js
index 75a7587782a9..a5a7d2bc3703 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/accessor/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/accessor/output.js
@@ -5,8 +5,7 @@ let Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       get: _get_foo,
       set: void 0
     });
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/field/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/field/output.js
index c83e48bcd86d..b5206a1f38e3 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/field/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/field/output.js
@@ -5,8 +5,7 @@ let Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/method/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/method/output.js
index ac675cbf7d85..32edd0cc6acf 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/method/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/method/output.js
@@ -5,8 +5,7 @@ let Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.add(this);
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
   }
 
   babelHelpers.createClass(Foo, [{
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/native-classes/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/native-classes/output.js
index 13ebbe421023..51e66218a8ab 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/native-classes/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/native-classes/output.js
@@ -2,7 +2,7 @@ var _bar = /*#__PURE__*/new WeakMap();
 
 class Foo {
   constructor() {
-    _bar.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _bar, {
       writable: true,
       value: "bar"
     });
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-other-redeclared/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-other-redeclared/output.js
index a54b7a6691f1..82f59fa0b443 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-other-redeclared/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-other-redeclared/output.js
@@ -7,13 +7,11 @@ let Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
-
-    _bar.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _bar, {
       writable: true,
       value: 1
     });
@@ -27,8 +25,7 @@ let Foo = /*#__PURE__*/function () {
       let Nested = /*#__PURE__*/function () {
         function Nested() {
           babelHelpers.classCallCheck(this, Nested);
-
-          _bar2.set(this, {
+          babelHelpers.classPrivateFieldInitSpec(this, _bar2, {
             writable: true,
             value: 2
           });
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-redeclared/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-redeclared/output.js
index 20a7183234aa..b9c7cf225570 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-redeclared/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class-redeclared/output.js
@@ -5,8 +5,7 @@ let Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
@@ -20,8 +19,7 @@ let Foo = /*#__PURE__*/function () {
       let Nested = /*#__PURE__*/function () {
         function Nested() {
           babelHelpers.classCallCheck(this, Nested);
-
-          _foo2.set(this, {
+          babelHelpers.classPrivateFieldInitSpec(this, _foo2, {
             writable: true,
             value: 2
           });
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class/output.js
index 2c52c716a1ee..57550078e7fc 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class/output.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/nested-class/output.js
@@ -5,8 +5,7 @@ let Foo = /*#__PURE__*/function () {
 
   function Foo() {
     babelHelpers.classCallCheck(this, Foo);
-
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: 1
     });
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/exec.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/exec.js
new file mode 100644
index 000000000000..673b1cced3af
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/exec.js
@@ -0,0 +1,17 @@
+class Test {
+
+  static #x = 1
+
+  method(other) {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return #x in other && Test;
+    }
+    return func() + Test;
+  }
+}
+
+const t = new Test();
+const t2 = new Test();
+expect(t.method(Test)).toBe(5)
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/input.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/input.js
new file mode 100644
index 000000000000..faa4ce3d104a
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/input.js
@@ -0,0 +1,13 @@
+class Test {
+
+  static #x = 1
+
+  method(other) {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return #x in other && Test;
+    }
+    return func() + Test;
+  }
+}
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/options.json b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/options.json
new file mode 100644
index 000000000000..19ed5174f545
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-properties"]
+}
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/output.js
new file mode 100644
index 000000000000..898d6a8ddcfb
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/static-shadow/output.js
@@ -0,0 +1,18 @@
+class Test {
+  method(other) {
+    const _Test2 = 2;
+
+    const func = () => {
+      const _Test = 3;
+      return other === Test && _Test;
+    };
+
+    return func() + _Test2;
+  }
+
+}
+
+var _x = {
+  writable: true,
+  value: 1
+};
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/exec.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/exec.js
new file mode 100644
index 000000000000..673b1cced3af
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/exec.js
@@ -0,0 +1,17 @@
+class Test {
+
+  static #x = 1
+
+  method(other) {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return #x in other && Test;
+    }
+    return func() + Test;
+  }
+}
+
+const t = new Test();
+const t2 = new Test();
+expect(t.method(Test)).toBe(5)
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/input.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/input.js
new file mode 100644
index 000000000000..faa4ce3d104a
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/input.js
@@ -0,0 +1,13 @@
+class Test {
+
+  static #x = 1
+
+  method(other) {
+    const Test = 2;
+    const func = () => {
+      const Test = 3;
+      return #x in other && Test;
+    }
+    return func() + Test;
+  }
+}
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/options.json b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/options.json
new file mode 100644
index 000000000000..19ed5174f545
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["proposal-class-properties"]
+}
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/output.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/output.js
new file mode 100644
index 000000000000..898d6a8ddcfb
--- /dev/null
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/static-shadow/output.js
@@ -0,0 +1,18 @@
+class Test {
+  method(other) {
+    const _Test2 = 2;
+
+    const func = () => {
+      const _Test = 3;
+      return other === Test && _Test;
+    };
+
+    return func() + _Test2;
+  }
+
+}
+
+var _x = {
+  writable: true,
+  value: 1
+};
diff --git a/packages/babel-plugin-syntax-class-static-block/.npmignore b/packages/babel-plugin-syntax-class-static-block/.npmignore
deleted file mode 100644
index f9806945836e..000000000000
--- a/packages/babel-plugin-syntax-class-static-block/.npmignore
+++ /dev/null
@@ -1,3 +0,0 @@
-src
-test
-*.log
diff --git a/packages/babel-plugin-syntax-class-static-block/README.md b/packages/babel-plugin-syntax-class-static-block/README.md
deleted file mode 100644
index 8dd2f6b32cb2..000000000000
--- a/packages/babel-plugin-syntax-class-static-block/README.md
+++ /dev/null
@@ -1,19 +0,0 @@
-# @babel/plugin-syntax-class-static-block
-
-> Allow parsing of class static blocks
-
-See our website [@babel/plugin-syntax-class-static-block](https://babeljs.io/docs/en/babel-plugin-syntax-class-static-block) for more information.
-
-## Install
-
-Using npm:
-
-```sh
-npm install --save-dev @babel/plugin-syntax-class-static-block
-```
-
-or using yarn:
-
-```sh
-yarn add @babel/plugin-syntax-class-static-block --dev
-```
diff --git a/packages/babel-plugin-syntax-class-static-block/package.json b/packages/babel-plugin-syntax-class-static-block/package.json
deleted file mode 100644
index c544de2f0aa3..000000000000
--- a/packages/babel-plugin-syntax-class-static-block/package.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "name": "@babel/plugin-syntax-class-static-block",
-  "version": "7.14.5",
-  "description": "Allow parsing of class static blocks",
-  "repository": {
-    "type": "git",
-    "url": "https://github.com/babel/babel.git",
-    "directory": "packages/babel-plugin-syntax-class-static-block"
-  },
-  "homepage": "https://babel.dev/docs/en/next/babel-plugin-syntax-class-static-block",
-  "license": "MIT",
-  "publishConfig": {
-    "access": "public"
-  },
-  "main": "./lib/index.js",
-  "exports": {
-    ".": "./lib/index.js"
-  },
-  "keywords": [
-    "babel-plugin"
-  ],
-  "dependencies": {
-    "@babel/helper-plugin-utils": "workspace:^7.14.5"
-  },
-  "peerDependencies": {
-    "@babel/core": "^7.0.0-0"
-  },
-  "engines": {
-    "node": ">=6.9.0"
-  },
-  "author": "The Babel Team (https://babel.dev/team)"
-}
diff --git a/packages/babel-plugin-syntax-class-static-block/src/index.js b/packages/babel-plugin-syntax-class-static-block/src/index.js
deleted file mode 100644
index 716fb853b288..000000000000
--- a/packages/babel-plugin-syntax-class-static-block/src/index.js
+++ /dev/null
@@ -1,13 +0,0 @@
-import { declare } from "@babel/helper-plugin-utils";
-
-export default declare(api => {
-  api.assertVersion(7);
-
-  return {
-    name: "syntax-class-static-block",
-
-    manipulateOptions(opts, parserOpts) {
-      parserOpts.plugins.push("classStaticBlock");
-    },
-  };
-});
diff --git a/packages/babel-plugin-syntax-private-property-in-object/.npmignore b/packages/babel-plugin-syntax-private-property-in-object/.npmignore
deleted file mode 100644
index f9806945836e..000000000000
--- a/packages/babel-plugin-syntax-private-property-in-object/.npmignore
+++ /dev/null
@@ -1,3 +0,0 @@
-src
-test
-*.log
diff --git a/packages/babel-plugin-syntax-private-property-in-object/README.md b/packages/babel-plugin-syntax-private-property-in-object/README.md
deleted file mode 100644
index 7869bc42241c..000000000000
--- a/packages/babel-plugin-syntax-private-property-in-object/README.md
+++ /dev/null
@@ -1,19 +0,0 @@
-# @babel/plugin-syntax-private-property-in-object
-
-> Allow parsing of '#foo in obj' brand checks
-
-See our website [@babel/plugin-syntax-private-property-in-object](https://babeljs.io/docs/en/babel-plugin-syntax-private-property-in-object) for more information.
-
-## Install
-
-Using npm:
-
-```sh
-npm install --save-dev @babel/plugin-syntax-private-property-in-object
-```
-
-or using yarn:
-
-```sh
-yarn add @babel/plugin-syntax-private-property-in-object --dev
-```
diff --git a/packages/babel-plugin-syntax-private-property-in-object/package.json b/packages/babel-plugin-syntax-private-property-in-object/package.json
deleted file mode 100644
index 8e66d3489700..000000000000
--- a/packages/babel-plugin-syntax-private-property-in-object/package.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "name": "@babel/plugin-syntax-private-property-in-object",
-  "version": "7.14.5",
-  "description": "Allow parsing of '#foo in obj' brand checks",
-  "repository": {
-    "type": "git",
-    "url": "https://github.com/babel/babel.git",
-    "directory": "packages/babel-plugin-syntax-private-property-in-object"
-  },
-  "homepage": "https://babel.dev/docs/en/next/babel-plugin-syntax-private-property-in-object",
-  "license": "MIT",
-  "publishConfig": {
-    "access": "public"
-  },
-  "main": "./lib/index.js",
-  "exports": {
-    ".": "./lib/index.js"
-  },
-  "keywords": [
-    "babel-plugin"
-  ],
-  "dependencies": {
-    "@babel/helper-plugin-utils": "workspace:^7.14.5"
-  },
-  "peerDependencies": {
-    "@babel/core": "^7.0.0-0"
-  },
-  "engines": {
-    "node": ">=6.9.0"
-  },
-  "author": "The Babel Team (https://babel.dev/team)"
-}
diff --git a/packages/babel-plugin-syntax-private-property-in-object/src/index.js b/packages/babel-plugin-syntax-private-property-in-object/src/index.js
deleted file mode 100644
index a716fe39e301..000000000000
--- a/packages/babel-plugin-syntax-private-property-in-object/src/index.js
+++ /dev/null
@@ -1,13 +0,0 @@
-import { declare } from "@babel/helper-plugin-utils";
-
-export default declare(api => {
-  api.assertVersion(7);
-
-  return {
-    name: "syntax-private-property-in-object",
-
-    manipulateOptions(opts, parserOpts) {
-      parserOpts.plugins.push("privateIn");
-    },
-  };
-});
diff --git a/packages/babel-plugin-syntax-top-level-await/.npmignore b/packages/babel-plugin-syntax-top-level-await/.npmignore
deleted file mode 100644
index cace0d6ddcdd..000000000000
--- a/packages/babel-plugin-syntax-top-level-await/.npmignore
+++ /dev/null
@@ -1,3 +0,0 @@
-node_modules
-*.log
-src
diff --git a/packages/babel-plugin-syntax-top-level-await/README.md b/packages/babel-plugin-syntax-top-level-await/README.md
deleted file mode 100644
index 040c3029e888..000000000000
--- a/packages/babel-plugin-syntax-top-level-await/README.md
+++ /dev/null
@@ -1,19 +0,0 @@
-# @babel/plugin-syntax-top-level-await
-
-> Allow parsing of top-level await in modules
-
-See our website [@babel/plugin-syntax-top-level-await](https://babeljs.io/docs/en/babel-plugin-syntax-top-level-await) for more information.
-
-## Install
-
-Using npm:
-
-```sh
-npm install --save-dev @babel/plugin-syntax-top-level-await
-```
-
-or using yarn:
-
-```sh
-yarn add @babel/plugin-syntax-top-level-await --dev
-```
diff --git a/packages/babel-plugin-syntax-top-level-await/package.json b/packages/babel-plugin-syntax-top-level-await/package.json
deleted file mode 100644
index beb95986edb8..000000000000
--- a/packages/babel-plugin-syntax-top-level-await/package.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "name": "@babel/plugin-syntax-top-level-await",
-  "version": "7.14.5",
-  "description": "Allow parsing of top-level await in modules",
-  "repository": {
-    "type": "git",
-    "url": "https://github.com/babel/babel.git",
-    "directory": "packages/babel-plugin-syntax-top-level-await"
-  },
-  "homepage": "https://babel.dev/docs/en/next/babel-plugin-syntax-top-level-await",
-  "license": "MIT",
-  "publishConfig": {
-    "access": "public"
-  },
-  "main": "./lib/index.js",
-  "keywords": [
-    "babel-plugin"
-  ],
-  "dependencies": {
-    "@babel/helper-plugin-utils": "workspace:^7.14.5"
-  },
-  "peerDependencies": {
-    "@babel/core": "^7.0.0-0"
-  },
-  "devDependencies": {
-    "@babel/core": "workspace:*"
-  },
-  "engines": {
-    "node": ">=6.9.0"
-  },
-  "author": "The Babel Team (https://babel.dev/team)"
-}
diff --git a/packages/babel-plugin-syntax-top-level-await/src/index.js b/packages/babel-plugin-syntax-top-level-await/src/index.js
deleted file mode 100644
index 2429b8ead657..000000000000
--- a/packages/babel-plugin-syntax-top-level-await/src/index.js
+++ /dev/null
@@ -1,13 +0,0 @@
-import { declare } from "@babel/helper-plugin-utils";
-
-export default declare(api => {
-  api.assertVersion(7);
-
-  return {
-    name: "syntax-top-level-await",
-
-    manipulateOptions(opts, parserOpts) {
-      parserOpts.plugins.push("topLevelAwait");
-    },
-  };
-});
diff --git a/packages/babel-plugin-transform-modules-commonjs/package.json b/packages/babel-plugin-transform-modules-commonjs/package.json
index ba70e8f99730..fc424ad7bbcc 100644
--- a/packages/babel-plugin-transform-modules-commonjs/package.json
+++ b/packages/babel-plugin-transform-modules-commonjs/package.json
@@ -28,6 +28,7 @@
     "@babel/core": "workspace:*",
     "@babel/helper-plugin-test-runner": "workspace:*",
     "@babel/plugin-external-helpers": "workspace:*",
+    "@babel/plugin-syntax-class-static-block": "^7.14.5",
     "@babel/plugin-syntax-object-rest-spread": "^7.8.3"
   },
   "homepage": "https://babel.dev/docs/en/next/babel-plugin-transform-modules-commonjs",
diff --git a/packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/class-static-block/options.json b/packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/class-static-block/options.json
index b14a64139e69..02226bec484a 100644
--- a/packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/class-static-block/options.json
+++ b/packages/babel-plugin-transform-modules-commonjs/test/fixtures/misc/class-static-block/options.json
@@ -1,3 +1,6 @@
 {
-  "plugins": ["transform-modules-commonjs", "syntax-class-static-block"]
+  "plugins": [
+    "transform-modules-commonjs",
+    "@babel/plugin-syntax-class-static-block"
+  ]
 }
diff --git a/packages/babel-plugin-transform-modules-systemjs/test/fixtures/tla/options.json b/packages/babel-plugin-transform-modules-systemjs/test/fixtures/tla/options.json
index 650b247545bf..38f13007daf6 100644
--- a/packages/babel-plugin-transform-modules-systemjs/test/fixtures/tla/options.json
+++ b/packages/babel-plugin-transform-modules-systemjs/test/fixtures/tla/options.json
@@ -1,3 +1,3 @@
 {
-  "plugins": ["transform-modules-systemjs", "syntax-top-level-await"]
+  "plugins": ["transform-modules-systemjs"]
 }
diff --git a/packages/babel-plugin-transform-typescript/src/namespace.ts b/packages/babel-plugin-transform-typescript/src/namespace.ts
index 2a24f156deac..186da7c3c77c 100644
--- a/packages/babel-plugin-transform-typescript/src/namespace.ts
+++ b/packages/babel-plugin-transform-typescript/src/namespace.ts
@@ -1,4 +1,5 @@
 import { template, types as t } from "@babel/core";
+import type { NodePath } from "@babel/traverse";
 
 export default function transpileNamespace(path, t, allowNamespaces) {
   if (path.node.declare || path.node.id.type === "StringLiteral") {
@@ -102,11 +103,34 @@ function handleVariableDeclaration(
   return [node, t.expressionStatement(t.sequenceExpression(assignments))];
 }
 
-function handleNested(path, t, node, parentExport?) {
+function buildNestedAmbiendModuleError(path: NodePath, node: t.Node) {
+  throw path.hub.buildError(
+    node,
+    "Ambient modules cannot be nested in other modules or namespaces.",
+    Error,
+  );
+}
+
+function handleNested(
+  path: NodePath,
+  t: typeof import("@babel/types"),
+  node: t.TSModuleDeclaration,
+  parentExport?,
+) {
   const names = new Set();
   const realName = node.id;
+  t.assertIdentifier(realName);
+
   const name = path.scope.generateUid(realName.name);
-  const namespaceTopLevel = node.body.body;
+
+  const namespaceTopLevel: t.Statement[] = t.isTSModuleBlock(node.body)
+    ? node.body.body
+    : // We handle `namespace X.Y {}` as if it was
+      //   namespace X {
+      //     export namespace Y {}
+      //   }
+      [t.exportNamedDeclaration(node.body)];
+
   for (let i = 0; i < namespaceTopLevel.length; i++) {
     const subNode = namespaceTopLevel[i];
 
@@ -114,6 +138,10 @@ function handleNested(path, t, node, parentExport?) {
     // declarations require further transformation.
     switch (subNode.type) {
       case "TSModuleDeclaration": {
+        if (!t.isIdentifier(subNode.id)) {
+          throw buildNestedAmbiendModuleError(path, subNode);
+        }
+
         const transformed = handleNested(path, t, subNode);
         const moduleName = subNode.id.name;
         if (names.has(moduleName)) {
@@ -181,6 +209,10 @@ function handleNested(path, t, node, parentExport?) {
         break;
       }
       case "TSModuleDeclaration": {
+        if (!t.isIdentifier(subNode.declaration.id)) {
+          throw buildNestedAmbiendModuleError(path, subNode.declaration);
+        }
+
         const transformed = handleNested(
           path,
           t,
@@ -204,7 +236,7 @@ function handleNested(path, t, node, parentExport?) {
   }
 
   // {}
-  let fallthroughValue = t.objectExpression([]);
+  let fallthroughValue: t.Expression = t.objectExpression([]);
 
   if (parentExport) {
     const memberExpr = t.memberExpression(parentExport, realName);
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested-exported/input.ts b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested-exported/input.ts
new file mode 100644
index 000000000000..58db7e4f66d9
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested-exported/input.ts
@@ -0,0 +1,3 @@
+namespace X {
+  export module "m" {}
+}
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested-exported/options.json b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested-exported/options.json
new file mode 100644
index 000000000000..653571301113
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested-exported/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "Ambient modules cannot be nested in other modules or namespaces."
+}
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested/input.ts b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested/input.ts
new file mode 100644
index 000000000000..35d3d38cb1f6
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested/input.ts
@@ -0,0 +1,3 @@
+namespace X {
+  module "m" {}
+}
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested/options.json b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested/options.json
new file mode 100644
index 000000000000..653571301113
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/ambient-module-nested/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "Ambient modules cannot be nested in other modules or namespaces."
+}
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand/input.ts b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand/input.ts
new file mode 100644
index 000000000000..8a39ba3d5e72
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand/input.ts
@@ -0,0 +1,7 @@
+namespace X.Y {
+  export const Z = 1;
+}
+
+namespace proj.data.util.api {
+  export const X = 1;
+}
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand/output.mjs b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand/output.mjs
new file mode 100644
index 000000000000..8c99a195f160
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/namespace/nested-shorthand/output.mjs
@@ -0,0 +1,27 @@
+let X;
+
+(function (_X) {
+  let Y;
+
+  (function (_Y) {
+    const Z = _Y.Z = 1;
+  })(Y || (Y = _X.Y || (_X.Y = {})));
+})(X || (X = {}));
+
+let proj;
+
+(function (_proj) {
+  let data;
+
+  (function (_data) {
+    let util;
+
+    (function (_util) {
+      let api;
+
+      (function (_api) {
+        const X = _api.X = 1;
+      })(api || (api = _util.api || (_util.api = {})));
+    })(util || (util = _data.util || (_data.util = {})));
+  })(data || (data = _proj.data || (_proj.data = {})));
+})(proj || (proj = {}));
diff --git a/packages/babel-preset-env/package.json b/packages/babel-preset-env/package.json
index ca7d5023c09e..bf7ad77907bb 100644
--- a/packages/babel-preset-env/package.json
+++ b/packages/babel-preset-env/package.json
@@ -38,7 +38,7 @@
     "@babel/plugin-proposal-unicode-property-regex": "workspace:^7.14.5",
     "@babel/plugin-syntax-async-generators": "^7.8.4",
     "@babel/plugin-syntax-class-properties": "^7.12.13",
-    "@babel/plugin-syntax-class-static-block": "workspace:^7.14.5",
+    "@babel/plugin-syntax-class-static-block": "^7.14.5",
     "@babel/plugin-syntax-dynamic-import": "^7.8.3",
     "@babel/plugin-syntax-export-namespace-from": "^7.8.3",
     "@babel/plugin-syntax-json-strings": "^7.8.3",
@@ -48,8 +48,8 @@
     "@babel/plugin-syntax-object-rest-spread": "^7.8.3",
     "@babel/plugin-syntax-optional-catch-binding": "^7.8.3",
     "@babel/plugin-syntax-optional-chaining": "^7.8.3",
-    "@babel/plugin-syntax-private-property-in-object": "workspace:^7.14.5",
-    "@babel/plugin-syntax-top-level-await": "workspace:^7.14.5",
+    "@babel/plugin-syntax-private-property-in-object": "^7.14.5",
+    "@babel/plugin-syntax-top-level-await": "^7.14.5",
     "@babel/plugin-transform-arrow-functions": "workspace:^7.14.5",
     "@babel/plugin-transform-async-to-generator": "workspace:^7.14.5",
     "@babel/plugin-transform-block-scoped-functions": "workspace:^7.14.5",
diff --git a/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/preset-not-loose-no-plugins/output.js b/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/preset-not-loose-no-plugins/output.js
index f3de7b04fc78..e411740434d3 100644
--- a/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/preset-not-loose-no-plugins/output.js
+++ b/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/preset-not-loose-no-plugins/output.js
@@ -2,8 +2,7 @@ var _foo = /*#__PURE__*/new WeakSet();
 
 class A {
   constructor() {
-    _foo.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
     babelHelpers.defineProperty(this, "x", 2);
   }
 
diff --git a/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-and-methods-not-loose-preset-loose/output.js b/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-and-methods-not-loose-preset-loose/output.js
index f3de7b04fc78..e411740434d3 100644
--- a/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-and-methods-not-loose-preset-loose/output.js
+++ b/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-and-methods-not-loose-preset-loose/output.js
@@ -2,8 +2,7 @@ var _foo = /*#__PURE__*/new WeakSet();
 
 class A {
   constructor() {
-    _foo.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
     babelHelpers.defineProperty(this, "x", 2);
   }
 
diff --git a/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-not-loose-preset-loose/output.js b/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-not-loose-preset-loose/output.js
index f3de7b04fc78..e411740434d3 100644
--- a/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-not-loose-preset-loose/output.js
+++ b/packages/babel-preset-env/test/fixtures/loose-class-features-precedence/properties-not-loose-preset-loose/output.js
@@ -2,8 +2,7 @@ var _foo = /*#__PURE__*/new WeakSet();
 
 class A {
   constructor() {
-    _foo.add(this);
-
+    babelHelpers.classPrivateMethodInitSpec(this, _foo);
     babelHelpers.defineProperty(this, "x", 2);
   }
 
diff --git a/packages/babel-preset-env/test/fixtures/shipped-proposals/new-class-features-firefox-70/output.js b/packages/babel-preset-env/test/fixtures/shipped-proposals/new-class-features-firefox-70/output.js
index 458142957dda..1cb775441ef3 100644
--- a/packages/babel-preset-env/test/fixtures/shipped-proposals/new-class-features-firefox-70/output.js
+++ b/packages/babel-preset-env/test/fixtures/shipped-proposals/new-class-features-firefox-70/output.js
@@ -2,7 +2,7 @@ var _foo = /*#__PURE__*/new WeakMap();
 
 class A {
   constructor() {
-    _foo.set(this, {
+    babelHelpers.classPrivateFieldInitSpec(this, _foo, {
       writable: true,
       value: void 0
     });
diff --git a/packages/babel-runtime-corejs2/package.json b/packages/babel-runtime-corejs2/package.json
index 0c9b04e96991..819ab3378ce5 100644
--- a/packages/babel-runtime-corejs2/package.json
+++ b/packages/babel-runtime-corejs2/package.json
@@ -801,6 +801,33 @@
       "./helpers/classPrivateMethodGet.js"
     ],
     "./helpers/esm/classPrivateMethodGet": "./helpers/esm/classPrivateMethodGet.js",
+    "./helpers/checkPrivateRedeclaration": [
+      {
+        "node": "./helpers/checkPrivateRedeclaration.js",
+        "import": "./helpers/esm/checkPrivateRedeclaration.js",
+        "default": "./helpers/checkPrivateRedeclaration.js"
+      },
+      "./helpers/checkPrivateRedeclaration.js"
+    ],
+    "./helpers/esm/checkPrivateRedeclaration": "./helpers/esm/checkPrivateRedeclaration.js",
+    "./helpers/classPrivateFieldInitSpec": [
+      {
+        "node": "./helpers/classPrivateFieldInitSpec.js",
+        "import": "./helpers/esm/classPrivateFieldInitSpec.js",
+        "default": "./helpers/classPrivateFieldInitSpec.js"
+      },
+      "./helpers/classPrivateFieldInitSpec.js"
+    ],
+    "./helpers/esm/classPrivateFieldInitSpec": "./helpers/esm/classPrivateFieldInitSpec.js",
+    "./helpers/classPrivateMethodInitSpec": [
+      {
+        "node": "./helpers/classPrivateMethodInitSpec.js",
+        "import": "./helpers/esm/classPrivateMethodInitSpec.js",
+        "default": "./helpers/classPrivateMethodInitSpec.js"
+      },
+      "./helpers/classPrivateMethodInitSpec.js"
+    ],
+    "./helpers/esm/classPrivateMethodInitSpec": "./helpers/esm/classPrivateMethodInitSpec.js",
     "./helpers/classPrivateMethodSet": [
       {
         "node": "./helpers/classPrivateMethodSet.js",
diff --git a/packages/babel-runtime-corejs3/package.json b/packages/babel-runtime-corejs3/package.json
index d0690a623eb2..8b4529b9c5a5 100644
--- a/packages/babel-runtime-corejs3/package.json
+++ b/packages/babel-runtime-corejs3/package.json
@@ -800,6 +800,33 @@
       "./helpers/classPrivateMethodGet.js"
     ],
     "./helpers/esm/classPrivateMethodGet": "./helpers/esm/classPrivateMethodGet.js",
+    "./helpers/checkPrivateRedeclaration": [
+      {
+        "node": "./helpers/checkPrivateRedeclaration.js",
+        "import": "./helpers/esm/checkPrivateRedeclaration.js",
+        "default": "./helpers/checkPrivateRedeclaration.js"
+      },
+      "./helpers/checkPrivateRedeclaration.js"
+    ],
+    "./helpers/esm/checkPrivateRedeclaration": "./helpers/esm/checkPrivateRedeclaration.js",
+    "./helpers/classPrivateFieldInitSpec": [
+      {
+        "node": "./helpers/classPrivateFieldInitSpec.js",
+        "import": "./helpers/esm/classPrivateFieldInitSpec.js",
+        "default": "./helpers/classPrivateFieldInitSpec.js"
+      },
+      "./helpers/classPrivateFieldInitSpec.js"
+    ],
+    "./helpers/esm/classPrivateFieldInitSpec": "./helpers/esm/classPrivateFieldInitSpec.js",
+    "./helpers/classPrivateMethodInitSpec": [
+      {
+        "node": "./helpers/classPrivateMethodInitSpec.js",
+        "import": "./helpers/esm/classPrivateMethodInitSpec.js",
+        "default": "./helpers/classPrivateMethodInitSpec.js"
+      },
+      "./helpers/classPrivateMethodInitSpec.js"
+    ],
+    "./helpers/esm/classPrivateMethodInitSpec": "./helpers/esm/classPrivateMethodInitSpec.js",
     "./helpers/classPrivateMethodSet": [
       {
         "node": "./helpers/classPrivateMethodSet.js",
diff --git a/packages/babel-runtime/package.json b/packages/babel-runtime/package.json
index c939ed29be80..759a72f5b9ed 100644
--- a/packages/babel-runtime/package.json
+++ b/packages/babel-runtime/package.json
@@ -800,6 +800,33 @@
       "./helpers/classPrivateMethodGet.js"
     ],
     "./helpers/esm/classPrivateMethodGet": "./helpers/esm/classPrivateMethodGet.js",
+    "./helpers/checkPrivateRedeclaration": [
+      {
+        "node": "./helpers/checkPrivateRedeclaration.js",
+        "import": "./helpers/esm/checkPrivateRedeclaration.js",
+        "default": "./helpers/checkPrivateRedeclaration.js"
+      },
+      "./helpers/checkPrivateRedeclaration.js"
+    ],
+    "./helpers/esm/checkPrivateRedeclaration": "./helpers/esm/checkPrivateRedeclaration.js",
+    "./helpers/classPrivateFieldInitSpec": [
+      {
+        "node": "./helpers/classPrivateFieldInitSpec.js",
+        "import": "./helpers/esm/classPrivateFieldInitSpec.js",
+        "default": "./helpers/classPrivateFieldInitSpec.js"
+      },
+      "./helpers/classPrivateFieldInitSpec.js"
+    ],
+    "./helpers/esm/classPrivateFieldInitSpec": "./helpers/esm/classPrivateFieldInitSpec.js",
+    "./helpers/classPrivateMethodInitSpec": [
+      {
+        "node": "./helpers/classPrivateMethodInitSpec.js",
+        "import": "./helpers/esm/classPrivateMethodInitSpec.js",
+        "default": "./helpers/classPrivateMethodInitSpec.js"
+      },
+      "./helpers/classPrivateMethodInitSpec.js"
+    ],
+    "./helpers/esm/classPrivateMethodInitSpec": "./helpers/esm/classPrivateMethodInitSpec.js",
     "./helpers/classPrivateMethodSet": [
       {
         "node": "./helpers/classPrivateMethodSet.js",
diff --git a/packages/babel-standalone/package.json b/packages/babel-standalone/package.json
index 109371265c4b..662d6d5f968a 100644
--- a/packages/babel-standalone/package.json
+++ b/packages/babel-standalone/package.json
@@ -34,7 +34,7 @@
     "@babel/plugin-proposal-unicode-property-regex": "workspace:*",
     "@babel/plugin-syntax-async-generators": "^7.8.4",
     "@babel/plugin-syntax-class-properties": "^7.12.13",
-    "@babel/plugin-syntax-class-static-block": "workspace:*",
+    "@babel/plugin-syntax-class-static-block": "^7.14.5",
     "@babel/plugin-syntax-decimal": "workspace:*",
     "@babel/plugin-syntax-decorators": "workspace:*",
     "@babel/plugin-syntax-do-expressions": "workspace:*",
@@ -50,7 +50,7 @@
     "@babel/plugin-syntax-optional-catch-binding": "^7.8.3",
     "@babel/plugin-syntax-pipeline-operator": "workspace:*",
     "@babel/plugin-syntax-record-and-tuple": "workspace:*",
-    "@babel/plugin-syntax-top-level-await": "workspace:*",
+    "@babel/plugin-syntax-top-level-await": "^7.14.5",
     "@babel/plugin-syntax-typescript": "workspace:*",
     "@babel/plugin-transform-arrow-functions": "workspace:*",
     "@babel/plugin-transform-async-to-generator": "workspace:*",
diff --git a/packages/babel-types/src/definitions/core.ts b/packages/babel-types/src/definitions/core.ts
index 6e275614e2be..fbf7e1859342 100644
--- a/packages/babel-types/src/definitions/core.ts
+++ b/packages/babel-types/src/definitions/core.ts
@@ -898,7 +898,12 @@ defineType("RestElement", {
     argument: {
       validate: !process.env.BABEL_TYPES_8_BREAKING
         ? assertNodeType("LVal")
-        : assertNodeType("Identifier", "Pattern", "MemberExpression"),
+        : assertNodeType(
+            "Identifier",
+            "ArrayPattern",
+            "ObjectPattern",
+            "MemberExpression",
+          ),
     },
     // For Flow
     optional: {
diff --git a/packages/babel-types/test/fields.js b/packages/babel-types/test/fields.js
index 13408b8c2f67..0a59c40b7df7 100644
--- a/packages/babel-types/test/fields.js
+++ b/packages/babel-types/test/fields.js
@@ -3,9 +3,10 @@ import glob from "glob";
 import path from "path";
 import fs from "fs";
 import { inspect } from "util";
+import { fileURLToPath } from "url";
 
-// eslint-disable-next-line no-restricted-globals
-const packages = path.resolve(__dirname, "..", "..");
+const dirname = path.dirname(fileURLToPath(import.meta.url));
+const packages = path.resolve(dirname, "..", "..");
 
 function readJson(file) {
   return new Promise((resolve, reject) => {
diff --git a/scripts/integration-tests/e2e-create-react-app.sh b/scripts/integration-tests/e2e-create-react-app.sh
index 02fb7f92b755..86fcfddc738d 100755
--- a/scripts/integration-tests/e2e-create-react-app.sh
+++ b/scripts/integration-tests/e2e-create-react-app.sh
@@ -17,6 +17,9 @@ set -x
 git clone --depth=1 https://github.com/facebook/create-react-app.git tmp/create-react-app
 cd tmp/create-react-app || exit
 
+# Update npm to v7
+npm i -g npm@7
+
 #==============================================================================#
 #                                   TEST                                       #
 #==============================================================================#
@@ -42,14 +45,10 @@ do
   (cd "$d"; node "$bump_deps")
 done
 
-# Don't use Yarn 2
-export YARN_IGNORE_PATH=1
-
 startLocalRegistry "$PWD"/../../verdaccio-config.yml
-yarn install
+npm install
 
 # Test
-CI=true yarn test
+CI=true npm run test
 
-unset YARN_IGNORE_PATH
 cleanup
diff --git a/yarn.lock b/yarn.lock
index a97bdbd6a272..7968e5db95f1 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -492,6 +492,7 @@ __metadata:
     "@babel/helper-plugin-test-runner": "workspace:*"
     "@babel/helper-replace-supers": "workspace:^7.15.0"
     "@babel/helper-split-export-declaration": "workspace:^7.14.5"
+    "@babel/plugin-syntax-class-static-block": ^7.14.5
     "@babel/preset-env": "workspace:*"
   peerDependencies:
     "@babel/core": ^7.0.0
@@ -1160,7 +1161,7 @@ __metadata:
     "@babel/helper-create-class-features-plugin": "workspace:^7.14.5"
     "@babel/helper-plugin-test-runner": "workspace:*"
     "@babel/helper-plugin-utils": "workspace:^7.14.5"
-    "@babel/plugin-syntax-class-static-block": "workspace:^7.14.5"
+    "@babel/plugin-syntax-class-static-block": ^7.14.5
   peerDependencies:
     "@babel/core": ^7.12.0
   languageName: unknown
@@ -1545,7 +1546,7 @@ __metadata:
     "@babel/helper-create-class-features-plugin": "workspace:^7.14.5"
     "@babel/helper-plugin-test-runner": "workspace:*"
     "@babel/helper-plugin-utils": "workspace:^7.14.5"
-    "@babel/plugin-syntax-private-property-in-object": "workspace:^7.14.5"
+    "@babel/plugin-syntax-private-property-in-object": ^7.14.5
   peerDependencies:
     "@babel/core": ^7.0.0-0
   languageName: unknown
@@ -1659,16 +1660,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@babel/plugin-syntax-class-static-block@workspace:*, @babel/plugin-syntax-class-static-block@workspace:^7.14.5, @babel/plugin-syntax-class-static-block@workspace:packages/babel-plugin-syntax-class-static-block":
-  version: 0.0.0-use.local
-  resolution: "@babel/plugin-syntax-class-static-block@workspace:packages/babel-plugin-syntax-class-static-block"
-  dependencies:
-    "@babel/helper-plugin-utils": "workspace:^7.14.5"
-  peerDependencies:
-    "@babel/core": ^7.0.0-0
-  languageName: unknown
-  linkType: soft
-
 "@babel/plugin-syntax-decimal@workspace:*, @babel/plugin-syntax-decimal@workspace:packages/babel-plugin-syntax-decimal":
   version: 0.0.0-use.local
   resolution: "@babel/plugin-syntax-decimal@workspace:packages/babel-plugin-syntax-decimal"
@@ -1931,16 +1922,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@babel/plugin-syntax-private-property-in-object@workspace:^7.14.5, @babel/plugin-syntax-private-property-in-object@workspace:packages/babel-plugin-syntax-private-property-in-object":
-  version: 0.0.0-use.local
-  resolution: "@babel/plugin-syntax-private-property-in-object@workspace:packages/babel-plugin-syntax-private-property-in-object"
-  dependencies:
-    "@babel/helper-plugin-utils": "workspace:^7.14.5"
-  peerDependencies:
-    "@babel/core": ^7.0.0-0
-  languageName: unknown
-  linkType: soft
-
 "@babel/plugin-syntax-record-and-tuple@workspace:*, @babel/plugin-syntax-record-and-tuple@workspace:^7.14.5, @babel/plugin-syntax-record-and-tuple@workspace:packages/babel-plugin-syntax-record-and-tuple":
   version: 0.0.0-use.local
   resolution: "@babel/plugin-syntax-record-and-tuple@workspace:packages/babel-plugin-syntax-record-and-tuple"
@@ -1974,17 +1955,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@babel/plugin-syntax-top-level-await@workspace:*, @babel/plugin-syntax-top-level-await@workspace:^7.14.5, @babel/plugin-syntax-top-level-await@workspace:packages/babel-plugin-syntax-top-level-await":
-  version: 0.0.0-use.local
-  resolution: "@babel/plugin-syntax-top-level-await@workspace:packages/babel-plugin-syntax-top-level-await"
-  dependencies:
-    "@babel/core": "workspace:*"
-    "@babel/helper-plugin-utils": "workspace:^7.14.5"
-  peerDependencies:
-    "@babel/core": ^7.0.0-0
-  languageName: unknown
-  linkType: soft
-
 "@babel/plugin-syntax-typescript@npm:^7.14.5, @babel/plugin-syntax-typescript@npm:^7.7.2":
   version: 7.14.5
   resolution: "@babel/plugin-syntax-typescript@npm:7.14.5"
@@ -2469,6 +2439,7 @@ __metadata:
     "@babel/helper-plugin-utils": "workspace:^7.14.5"
     "@babel/helper-simple-access": "workspace:^7.14.8"
     "@babel/plugin-external-helpers": "workspace:*"
+    "@babel/plugin-syntax-class-static-block": ^7.14.5
     "@babel/plugin-syntax-object-rest-spread": ^7.8.3
     babel-plugin-dynamic-import-node: ^2.3.3
   peerDependencies:
@@ -3228,7 +3199,7 @@ __metadata:
     "@babel/plugin-proposal-unicode-property-regex": "workspace:^7.14.5"
     "@babel/plugin-syntax-async-generators": ^7.8.4
     "@babel/plugin-syntax-class-properties": ^7.12.13
-    "@babel/plugin-syntax-class-static-block": "workspace:^7.14.5"
+    "@babel/plugin-syntax-class-static-block": ^7.14.5
     "@babel/plugin-syntax-dynamic-import": ^7.8.3
     "@babel/plugin-syntax-export-namespace-from": ^7.8.3
     "@babel/plugin-syntax-json-strings": ^7.8.3
@@ -3238,8 +3209,8 @@ __metadata:
     "@babel/plugin-syntax-object-rest-spread": ^7.8.3
     "@babel/plugin-syntax-optional-catch-binding": ^7.8.3
     "@babel/plugin-syntax-optional-chaining": ^7.8.3
-    "@babel/plugin-syntax-private-property-in-object": "workspace:^7.14.5"
-    "@babel/plugin-syntax-top-level-await": "workspace:^7.14.5"
+    "@babel/plugin-syntax-private-property-in-object": ^7.14.5
+    "@babel/plugin-syntax-top-level-await": ^7.14.5
     "@babel/plugin-transform-arrow-functions": "workspace:^7.14.5"
     "@babel/plugin-transform-async-to-generator": "workspace:^7.14.5"
     "@babel/plugin-transform-block-scoped-functions": "workspace:^7.14.5"
@@ -3467,7 +3438,7 @@ __metadata:
     "@babel/plugin-proposal-unicode-property-regex": "workspace:*"
     "@babel/plugin-syntax-async-generators": ^7.8.4
     "@babel/plugin-syntax-class-properties": ^7.12.13
-    "@babel/plugin-syntax-class-static-block": "workspace:*"
+    "@babel/plugin-syntax-class-static-block": ^7.14.5
     "@babel/plugin-syntax-decimal": "workspace:*"
     "@babel/plugin-syntax-decorators": "workspace:*"
     "@babel/plugin-syntax-do-expressions": "workspace:*"
@@ -3483,7 +3454,7 @@ __metadata:
     "@babel/plugin-syntax-optional-catch-binding": ^7.8.3
     "@babel/plugin-syntax-pipeline-operator": "workspace:*"
     "@babel/plugin-syntax-record-and-tuple": "workspace:*"
-    "@babel/plugin-syntax-top-level-await": "workspace:*"
+    "@babel/plugin-syntax-top-level-await": ^7.14.5
     "@babel/plugin-syntax-typescript": "workspace:*"
     "@babel/plugin-transform-arrow-functions": "workspace:*"
     "@babel/plugin-transform-async-to-generator": "workspace:*"