diff --git a/lib/optimizer.js b/lib/optimizer.js
index 8e79901..705f510 100644
--- a/lib/optimizer.js
+++ b/lib/optimizer.js
@@ -82,11 +82,13 @@ const optimize = (compiler, [file, originalSource], compilation, opts, classGene
   compilation.updateAsset(file, source);
 };
 
-const optimizer = (compiler, compilation, opts) => (assets) => {
+const optimizer = (opts) => {
   if (!opts.classNameRegExp) throw new Error("'classNameRegExp' option is required. e.g. '[c]-[a-z][a-zA-Z0-9_]*'");
   const classGenerator = new ClassGenerator();
-  Object.entries(assets).forEach((asset) => optimize(compiler, asset, compilation, opts, classGenerator));
-  validate(opts, classGenerator);
+  return (compiler, compilation, assets) => {
+    Object.entries(assets).forEach((asset) => optimize(compiler, asset, compilation, opts, classGenerator));
+    validate(opts, classGenerator);
+  };
 }
 
 module.exports = optimizer;
diff --git a/lib/plugin.js b/lib/plugin.js
index 9eddcef..4ff37e6 100644
--- a/lib/plugin.js
+++ b/lib/plugin.js
@@ -1,9 +1,15 @@
 const optimizer = require('./optimizer');
+let HtmlWebpackPlugin = null;
+try {
+  HtmlWebpackPlugin = require('html-webpack-plugin');
+} catch {
+  // ignore
+}
 
-const runner = (compiler, compilation, opts) => {
-  const optimize = optimizer(compiler, compilation, opts);
-  return (chunks, callback) => {
-    optimize(chunks);
+const runner = (opts) => {
+  const optimize = optimizer(opts);
+  return (compiler, compilation, chunks, callback) => {
+    optimize(compiler, compilation, chunks);
     callback();
   };
 }
@@ -17,7 +23,18 @@ class Plugin {
     compiler.hooks.compilation.tap(
       'MangleCssClassPluginHooks',
       (compilation) => {
-        compilation.hooks.processAssets.tapAsync('MangleCssClassPluginOptimizeChunkAssetsHooks', runner(compiler, compilation, this.opts));
+        if (!this.fn) {
+          this.fn = runner(this.opts);
+        }
+        if (HtmlWebpackPlugin) {
+          HtmlWebpackPlugin.getHooks(compilation).afterEmit.tapAsync(
+            'MangleCssClassPluginOptimizeChunkAssetsHooks',
+            (data, callback) => {
+              this.fn(compiler, compilation, { [data.outputName]: compilation.assets[data.outputName] }, callback);
+            },
+          );
+        }
+        compilation.hooks.processAssets.tapAsync('MangleCssClassPluginOptimizeChunkAssetsHooks', (chunks, callback) => this.fn(compiler, compilation, chunks, callback));
       }
     );
   }