diff --git a/src/hooks.js b/src/hooks.js
deleted file mode 100644
index 5b03cd72..00000000
--- a/src/hooks.js
+++ /dev/null
@@ -1,35 +0,0 @@
-const { SyncWaterfallHook } = require("tapable");
-
-/** @typedef {import("webpack").Compilation} Compilation */
-/**
- * @typedef {Object} VarNames
- * @property {string} tag
- * @property {string} chunkId
- * @property {string} href
- * @property {string} resolve
- * @property {string} reject
- */
-
-/**
- * @typedef {Object} MiniCssExtractPluginCompilationHooks
- * @property {import("tapable").SyncWaterfallHook<[string, VarNames], string>} beforeTagInsert
- */
-
-/** @type {WeakMap<Compilation, MiniCssExtractPluginCompilationHooks>} */
-const compilationHooksMap = new WeakMap();
-
-/**
- *
- * @param {Compilation} compilation the compilation
- * @returns {MiniCssExtractPluginCompilationHooks} the compilation hooks
- */
-exports.getCompilationHooks = function getCompilationHooks(compilation) {
-  let hooks = compilationHooksMap.get(compilation);
-  if (!hooks) {
-    hooks = {
-      beforeTagInsert: new SyncWaterfallHook(["source", "varNames"], "string"),
-    };
-    compilationHooksMap.set(compilation, hooks);
-  }
-  return hooks;
-};
diff --git a/src/index.js b/src/index.js
index 6d344585..d8fc28f8 100644
--- a/src/index.js
+++ b/src/index.js
@@ -3,6 +3,7 @@
 const path = require("path");
 
 const { validate } = require("schema-utils");
+const { SyncWaterfallHook } = require("tapable");
 
 const schema = require("./plugin-options.json");
 const {
@@ -15,7 +16,6 @@ const {
   getUndoPath,
   BASE_URI,
 } = require("./utils");
-const { getCompilationHooks } = require("./hooks");
 
 /** @typedef {import("schema-utils/declarations/validate").Schema} Schema */
 /** @typedef {import("webpack").Compiler} Compiler */
@@ -89,16 +89,23 @@ const CODE_GENERATION_RESULT = {
 };
 
 /** @typedef {Module & { content: Buffer, media?: string, sourceMap?: Buffer, supports?: string, layer?: string, assets?: { [key: string]: TODO }, assetsInfo?: Map<string, AssetInfo> }} CssModule */
-
 /** @typedef {{ context: string | null, identifier: string, identifierIndex: number, content: Buffer, sourceMap?: Buffer, media?: string, supports?: string, layer?: TODO, assetsInfo?: Map<string, AssetInfo>, assets?: { [key: string]: TODO }}} CssModuleDependency */
-
 /** @typedef {{ new(dependency: CssModuleDependency): CssModule }} CssModuleConstructor */
-
 /** @typedef {Dependency & CssModuleDependency} CssDependency */
-
 /** @typedef {Omit<LoaderDependency, "context">} CssDependencyOptions */
-
 /** @typedef {{ new(loaderDependency: CssDependencyOptions, context: string | null, identifierIndex: number): CssDependency }} CssDependencyConstructor */
+/**
+ * @typedef {Object} VarNames
+ * @property {string} tag
+ * @property {string} chunkId
+ * @property {string} href
+ * @property {string} resolve
+ * @property {string} reject
+ */
+/**
+ * @typedef {Object} MiniCssExtractPluginCompilationHooks
+ * @property {import("tapable").SyncWaterfallHook<[string, VarNames], string>} beforeTagInsert
+ */
 
 /**
  *
@@ -114,6 +121,9 @@ const cssDependencyCache = new WeakMap();
  */
 const registered = new WeakSet();
 
+/** @type {WeakMap<Compilation, MiniCssExtractPluginCompilationHooks>} */
+const compilationHooksMap = new WeakMap();
+
 class MiniCssExtractPlugin {
   /**
    * @param {Compiler["webpack"]} webpack
@@ -519,7 +529,19 @@ class MiniCssExtractPlugin {
    * @param {Compilation} compilation
    */
   static getCompilationHooks(compilation) {
-    return getCompilationHooks(compilation);
+    let hooks = compilationHooksMap.get(compilation);
+
+    if (!hooks) {
+      hooks = {
+        beforeTagInsert: new SyncWaterfallHook(
+          ["source", "varNames"],
+          "string"
+        ),
+      };
+      compilationHooksMap.set(compilation, hooks);
+    }
+
+    return hooks;
   }
 
   /**
diff --git a/test/cases/chunkFilename-fullhash/expected/webpack-5/0.04f5273a6b9819ed9e63.css b/test/cases/chunkFilename-fullhash/expected/webpack-5/0.32b536df514e34b610fa.css
similarity index 100%
rename from test/cases/chunkFilename-fullhash/expected/webpack-5/0.04f5273a6b9819ed9e63.css
rename to test/cases/chunkFilename-fullhash/expected/webpack-5/0.32b536df514e34b610fa.css
diff --git a/test/cases/chunkFilename-fullhash/expected/webpack-5/04f5273a6b9819ed9e63.css b/test/cases/chunkFilename-fullhash/expected/webpack-5/32b536df514e34b610fa.css
similarity index 100%
rename from test/cases/chunkFilename-fullhash/expected/webpack-5/04f5273a6b9819ed9e63.css
rename to test/cases/chunkFilename-fullhash/expected/webpack-5/32b536df514e34b610fa.css
diff --git a/test/cases/chunkFilename-fullhash/expected/webpack-5/main.js b/test/cases/chunkFilename-fullhash/expected/webpack-5/main.js
index 84f5a0c2..11b3f48d 100644
--- a/test/cases/chunkFilename-fullhash/expected/webpack-5/main.js
+++ b/test/cases/chunkFilename-fullhash/expected/webpack-5/main.js
@@ -73,7 +73,7 @@ __webpack_require__.r(__webpack_exports__);
 /******/ 	
 /******/ 	/* webpack/runtime/getFullHash */
 /******/ 	(() => {
-/******/ 		__webpack_require__.h = () => ("04f5273a6b9819ed9e63")
+/******/ 		__webpack_require__.h = () => ("32b536df514e34b610fa")
 /******/ 	})();
 /******/ 	
 /******/ 	/* webpack/runtime/global */
diff --git a/types/index.d.ts b/types/index.d.ts
index 5aa18062..0765eb15 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -18,7 +18,7 @@ declare class MiniCssExtractPlugin {
    */
   static getCompilationHooks(
     compilation: Compilation
-  ): import("./hooks").MiniCssExtractPluginCompilationHooks;
+  ): MiniCssExtractPluginCompilationHooks;
   /**
    * @param {PluginOptions} [options]
    */
@@ -101,6 +101,8 @@ declare namespace MiniCssExtractPlugin {
     CssDependency,
     CssDependencyOptions,
     CssDependencyConstructor,
+    VarNames,
+    MiniCssExtractPluginCompilationHooks,
   };
 }
 type Compiler = import("webpack").Compiler;
@@ -111,6 +113,12 @@ type CssDependencyConstructor = new (
   identifierIndex: number
 ) => CssDependency;
 type Compilation = import("webpack").Compilation;
+type MiniCssExtractPluginCompilationHooks = {
+  beforeTagInsert: import("tapable").SyncWaterfallHook<
+    [string, VarNames],
+    string
+  >;
+};
 type PluginOptions = {
   filename?: Required<Configuration>["output"]["filename"];
   chunkFilename?: Required<Configuration>["output"]["chunkFilename"];
@@ -240,3 +248,10 @@ type CssModuleDependency = {
 };
 type CssDependency = Dependency & CssModuleDependency;
 type CssDependencyOptions = Omit<LoaderDependency, "context">;
+type VarNames = {
+  tag: string;
+  chunkId: string;
+  href: string;
+  resolve: string;
+  reject: string;
+};