diff --git a/packages/dtslint/dtslint.json b/packages/dtslint/dtslint.json
index 3bd1e69c1f..e49c6c83f4 100644
--- a/packages/dtslint/dtslint.json
+++ b/packages/dtslint/dtslint.json
@@ -10,7 +10,6 @@
         "no-relative-import-in-test": true,
         "strict-export-declare-modifiers": true,
         "no-single-declare-module": true,
-        "prefer-declare-function": true,
         "unified-signatures": true,
         "void-return": true,
         "npm-naming": true,
diff --git a/packages/dtslint/src/rules/prefer-declare-function.ts b/packages/dtslint/src/rules/prefer-declare-function.ts
new file mode 100644
index 0000000000..11d1b2c009
--- /dev/null
+++ b/packages/dtslint/src/rules/prefer-declare-function.ts
@@ -0,0 +1,37 @@
+import { AST_NODE_TYPES, TSESTree } from "@typescript-eslint/utils";
+
+import { createRule } from "../util";
+
+const rule = createRule({
+  defaultOptions: [],
+  meta: {
+    docs: {
+      description: "Forbids `const x: () => void`.",
+      recommended: "error",
+    },
+    messages: {
+      variableFunction: "Use a function declaration instead of a variable of function type.",
+    },
+    schema: [],
+    type: "problem",
+  },
+  name: "prefer-declare-function",
+  create(context) {
+    return {
+      // eslint-disable-next-line @typescript-eslint/naming-convention
+      "VariableDeclaration > VariableDeclarator"(node: TSESTree.VariableDeclarator) {
+        if (
+          node.id.typeAnnotation?.typeAnnotation.type === AST_NODE_TYPES.TSFunctionType &&
+          context.getFilename().endsWith(".d.ts")
+        ) {
+          context.report({
+            messageId: "variableFunction",
+            node: node.id,
+          });
+        }
+      },
+    };
+  },
+});
+
+export = rule;
diff --git a/packages/dtslint/src/rules/preferDeclareFunctionRule.ts b/packages/dtslint/src/rules/preferDeclareFunctionRule.ts
deleted file mode 100644
index b6bcb5c9d9..0000000000
--- a/packages/dtslint/src/rules/preferDeclareFunctionRule.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-import * as Lint from "tslint";
-import * as ts from "typescript";
-
-import { eachModuleStatement, failure } from "../util";
-
-export class Rule extends Lint.Rules.AbstractRule {
-  static metadata: Lint.IRuleMetadata = {
-    ruleName: "prefer-declare-function",
-    description: "Forbids `export const x = () => void`.",
-    optionsDescription: "Not configurable.",
-    options: null,
-    type: "style",
-    typescriptOnly: true,
-  };
-
-  static FAILURE_STRING = failure(
-    Rule.metadata.ruleName,
-    "Use a function declaration instead of a variable of function type."
-  );
-
-  apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
-    return this.applyWithFunction(sourceFile, walk);
-  }
-}
-
-function walk(ctx: Lint.WalkContext<void>): void {
-  eachModuleStatement(ctx.sourceFile, (statement) => {
-    if (ts.isVariableStatement(statement)) {
-      for (const varDecl of statement.declarationList.declarations) {
-        if (varDecl.type !== undefined && varDecl.type.kind === ts.SyntaxKind.FunctionType) {
-          ctx.addFailureAtNode(varDecl, Rule.FAILURE_STRING);
-        }
-      }
-    }
-  });
-}
diff --git a/packages/dtslint/test/prefer-declare-function.test.ts b/packages/dtslint/test/prefer-declare-function.test.ts
new file mode 100644
index 0000000000..ff52afeabe
--- /dev/null
+++ b/packages/dtslint/test/prefer-declare-function.test.ts
@@ -0,0 +1,66 @@
+import { ESLintUtils } from "@typescript-eslint/utils";
+
+import * as preferDeclareFunction from "../src/rules/prefer-declare-function";
+
+const ruleTester = new ESLintUtils.RuleTester({
+  parser: "@typescript-eslint/parser",
+});
+
+ruleTester.run("prefer-declare-function", preferDeclareFunction, {
+  invalid: [
+    {
+      filename: "index.d.ts",
+      code: `export const example: () => void;`,
+      errors: [
+        {
+          column: 14,
+          endColumn: 33,
+          line: 1,
+          messageId: "variableFunction",
+        },
+      ],
+    },
+    {
+      filename: "index.d.ts",
+      code: `
+        namespace N {
+            export const example: () => void;
+        }
+`,
+      errors: [
+        {
+          column: 26,
+          endColumn: 45,
+          line: 3,
+          messageId: "variableFunction",
+        },
+      ],
+    },
+    {
+      filename: "index.d.ts",
+      code: `
+        namespace N {
+            const example: () => void;
+        }
+`,
+      errors: [
+        {
+          column: 19,
+          endColumn: 38,
+          line: 3,
+          messageId: "variableFunction",
+        },
+      ],
+    },
+  ],
+  valid: [
+    {
+      filename: "index.d.ts",
+      code: `function example(): void`,
+    },
+    {
+      filename: "test.ts",
+      code: `export const example: () => void;`,
+    },
+  ],
+});
diff --git a/packages/dtslint/test/prefer-declare-function/test.d.ts.lint b/packages/dtslint/test/prefer-declare-function/test.d.ts.lint
deleted file mode 100644
index 85f9c61011..0000000000
--- a/packages/dtslint/test/prefer-declare-function/test.d.ts.lint
+++ /dev/null
@@ -1,10 +0,0 @@
-export const x: () => void;
-             ~~~~~~~~~~~~~ [0]
-
-namespace N {
-    const x: () => void;
-          ~~~~~~~~~~~~~ [0]
-}
-
-
-[0]: Use a function declaration instead of a variable of function type. See: https://github.com/microsoft/DefinitelyTyped-tools/blob/master/packages/dtslint/docs/prefer-declare-function.md
diff --git a/packages/dtslint/test/prefer-declare-function/tslint.json b/packages/dtslint/test/prefer-declare-function/tslint.json
deleted file mode 100644
index 06473197a7..0000000000
--- a/packages/dtslint/test/prefer-declare-function/tslint.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-  "rulesDirectory": ["../../dist/rules"],
-  "rules": {
-    "prefer-declare-function": true
-  }
-}