diff --git a/packages/eslint-plugin/package.json b/packages/eslint-plugin/package.json
index b9edae01e6a..c1de7347c65 100644
--- a/packages/eslint-plugin/package.json
+++ b/packages/eslint-plugin/package.json
@@ -46,6 +46,7 @@
     "@typescript-eslint/scope-manager": "4.12.0",
     "debug": "^4.1.1",
     "functional-red-black-tree": "^1.0.1",
+    "lodash": "^4.17.15",
     "regexpp": "^3.0.0",
     "semver": "^7.3.2",
     "tsutils": "^3.17.1"
diff --git a/packages/eslint-plugin/src/rules/no-redeclare.ts b/packages/eslint-plugin/src/rules/no-redeclare.ts
index d85cb1dc241..fa67859f509 100644
--- a/packages/eslint-plugin/src/rules/no-redeclare.ts
+++ b/packages/eslint-plugin/src/rules/no-redeclare.ts
@@ -13,43 +13,6 @@ type Options = [
   },
 ];
 
-// https://github.com/lodash/lodash/blob/86a852fe763935bb64c12589df5391fd7d3bb14d/escapeRegExp.js
-const reRegExpChar = /[\\^$.*+?()[\]{}|]/g;
-const reHasRegExpChar = RegExp(reRegExpChar.source);
-function escapeRegExp(str: string): string {
-  return str && reHasRegExpChar.test(str)
-    ? str.replace(reRegExpChar, '\\$&')
-    : str || '';
-}
-
-function getNameLocationInGlobalDirectiveComment(
-  sourceCode: TSESLint.SourceCode,
-  comment: TSESTree.Comment,
-  name: string,
-): TSESTree.SourceLocation {
-  const namePattern = new RegExp(
-    `[\\s,]${escapeRegExp(name)}(?:$|[\\s,:])`,
-    'gu',
-  );
-
-  // To ignore the first text "global".
-  namePattern.lastIndex = comment.value.indexOf('global') + 6;
-
-  // Search a given variable name.
-  const match = namePattern.exec(comment.value);
-
-  // Convert the index to loc.
-  const start = sourceCode.getLocFromIndex(
-    comment.range[0] + '/*'.length + (match ? match.index + 1 : 0),
-  );
-  const end = {
-    line: start.line,
-    column: start.column + (match ? name.length : 1),
-  };
-
-  return { start, end };
-}
-
 export default util.createRule<Options, MessageIds>({
   name: 'no-redeclare',
   meta: {
@@ -129,7 +92,7 @@ export default util.createRule<Options, MessageIds>({
           yield {
             type: 'comment',
             node: comment,
-            loc: getNameLocationInGlobalDirectiveComment(
+            loc: util.getNameLocationInGlobalDirectiveComment(
               sourceCode,
               comment,
               variable.name,
diff --git a/packages/eslint-plugin/src/rules/no-unused-vars.ts b/packages/eslint-plugin/src/rules/no-unused-vars.ts
index 6b96151e959..968c8d51b54 100644
--- a/packages/eslint-plugin/src/rules/no-unused-vars.ts
+++ b/packages/eslint-plugin/src/rules/no-unused-vars.ts
@@ -4,7 +4,6 @@ import {
   TSESTree,
 } from '@typescript-eslint/experimental-utils';
 import { PatternVisitor } from '@typescript-eslint/scope-manager';
-import { getNameLocationInGlobalDirectiveComment } from 'eslint/lib/rules/utils/ast-utils';
 import * as util from '../util';
 
 export type MessageIds = 'unusedVar';
@@ -388,7 +387,7 @@ export default util.createRule<Options, MessageIds>({
 
             context.report({
               node: programNode,
-              loc: getNameLocationInGlobalDirectiveComment(
+              loc: util.getNameLocationInGlobalDirectiveComment(
                 sourceCode,
                 directiveComment,
                 unusedVar.name,
diff --git a/packages/eslint-plugin/src/util/astUtils.ts b/packages/eslint-plugin/src/util/astUtils.ts
index 12f003e98d0..53ad3f116e6 100644
--- a/packages/eslint-plugin/src/util/astUtils.ts
+++ b/packages/eslint-plugin/src/util/astUtils.ts
@@ -1,2 +1,43 @@
+import type { TSESLint, TSESTree } from '@typescript-eslint/experimental-utils';
+import escapeRegExp from 'lodash/escapeRegExp';
+
 // deeply re-export, for convenience
 export * from '@typescript-eslint/experimental-utils/dist/ast-utils';
+
+// The following is copied from `eslint`'s source code since it doesn't exist in eslint@5.
+// https://github.com/eslint/eslint/blob/145aec1ab9052fbca96a44d04927c595951b1536/lib/rules/utils/ast-utils.js#L1751-L1779
+// Could be export { getNameLocationInGlobalDirectiveComment } from 'eslint/lib/rules/utils/ast-utils'
+/**
+ * Get the `loc` object of a given name in a `/*globals` directive comment.
+ * @param {SourceCode} sourceCode The source code to convert index to loc.
+ * @param {Comment} comment The `/*globals` directive comment which include the name.
+ * @param {string} name The name to find.
+ * @returns {SourceLocation} The `loc` object.
+ */
+export function getNameLocationInGlobalDirectiveComment(
+  sourceCode: TSESLint.SourceCode,
+  comment: TSESTree.Comment,
+  name: string,
+): TSESTree.SourceLocation {
+  const namePattern = new RegExp(
+    `[\\s,]${escapeRegExp(name)}(?:$|[\\s,:])`,
+    'gu',
+  );
+
+  // To ignore the first text "global".
+  namePattern.lastIndex = comment.value.indexOf('global') + 6;
+
+  // Search a given variable name.
+  const match = namePattern.exec(comment.value);
+
+  // Convert the index to loc.
+  const start = sourceCode.getLocFromIndex(
+    comment.range[0] + '/*'.length + (match ? match.index + 1 : 0),
+  );
+  const end = {
+    line: start.line,
+    column: start.column + (match ? name.length : 1),
+  };
+
+  return { start, end };
+}
diff --git a/packages/eslint-plugin/typings/eslint-rules.d.ts b/packages/eslint-plugin/typings/eslint-rules.d.ts
index e25ce02f88b..ca726d6fb83 100644
--- a/packages/eslint-plugin/typings/eslint-rules.d.ts
+++ b/packages/eslint-plugin/typings/eslint-rules.d.ts
@@ -830,17 +830,3 @@ declare module 'eslint/lib/rules/prefer-const' {
   >;
   export = rule;
 }
-
-declare module 'eslint/lib/rules/utils/ast-utils' {
-  import { TSESLint, TSESTree } from '@typescript-eslint/experimental-utils';
-
-  const utils: {
-    getNameLocationInGlobalDirectiveComment(
-      sourceCode: TSESLint.SourceCode,
-      comment: TSESTree.Comment,
-      name: string,
-    ): TSESTree.SourceLocation;
-  };
-
-  export = utils;
-}