diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/assumption-privateFieldsAsProperties/rhs-not-object/exec.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/assumption-privateFieldsAsProperties/rhs-not-object/exec.js
index 412b37f1946d..1065753a6b36 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/assumption-privateFieldsAsProperties/rhs-not-object/exec.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/assumption-privateFieldsAsProperties/rhs-not-object/exec.js
@@ -1,27 +1,27 @@
-expect(() => class { static #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p() {}; static q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p() {}; static q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p() {}; q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p() {}; q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p() {}; q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p() {}; q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p() {}; q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/rhs-not-object/exec.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/rhs-not-object/exec.js
index 412b37f1946d..1065753a6b36 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/rhs-not-object/exec.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private-loose/rhs-not-object/exec.js
@@ -1,27 +1,27 @@
-expect(() => class { static #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p() {}; static q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p() {}; static q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p() {}; q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p() {}; q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p() {}; q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p() {}; q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p() {}; q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/rhs-not-object/exec.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/rhs-not-object/exec.js
index 412b37f1946d..1065753a6b36 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/rhs-not-object/exec.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/private/rhs-not-object/exec.js
@@ -1,27 +1,27 @@
-expect(() => class { static #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p() {}; static q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p() {}; static q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p() {}; q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p() {}; q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p() {}; q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p() {}; q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p() {}; q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
diff --git a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/rhs-not-object/exec.js b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/rhs-not-object/exec.js
index 412b37f1946d..1065753a6b36 100644
--- a/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/rhs-not-object/exec.js
+++ b/packages/babel-plugin-proposal-private-property-in-object/test/fixtures/to-native-fields/rhs-not-object/exec.js
@@ -1,27 +1,27 @@
-expect(() => class { static #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => class { static #p() {}; static q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => class { static #p() {}; static q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => class { static #p() {}; static q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => class { static #p() {}; static q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");
 
-expect(() => new class { #p() {}; q = #p in 0 }).toThrowError(`right-hand side of 'in' should be an object, got number`);
-expect(() => new class { #p() {}; q = #p in "" }).toThrowError(`right-hand side of 'in' should be an object, got string`);
-expect(() => new class { #p() {}; q = #p in true }).toThrowError(`right-hand side of 'in' should be an object, got boolean`);
-expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError(`right-hand side of 'in' should be an object, got undefined`);
-expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError(`right-hand side of 'in' should be an object, got symbol`);
-expect(() => new class { #p() {}; q = #p in 0n }).toThrowError(`right-hand side of 'in' should be an object, got bigint`);
+expect(() => new class { #p() {}; q = #p in 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in "" }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in true }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in void 0 }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in Symbol.iterator }).toThrowError("Cannot use 'in' operator to search for '0'");
+expect(() => new class { #p() {}; q = #p in 0n }).toThrowError("Cannot use 'in' operator to search for '0'");