diff --git a/README.md b/README.md
index 5df0b61..989aef7 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,19 @@ ignorePrefixRegExp: '((hover|focus|xs|md|sm|lg|xl)[\\\\]*:)*',
 ```
 In this case, `hover\:xs\:c-textbox__input` becomes `hover\:xs\:a`.
 
+#### classGenerator
+Override the default class name generator.  
+
+```js
+// original: original class name
+// opts: options of the plugin
+// context: own context of the class generator(initial value is just an empty object)
+classGenerator: (original, opts, context) => {
+  // return custom generated class name.
+  // Or return undefined if you want to leave it to the original behavior.
+}
+```
+
 ### Example
 #### Source code
 ```html
diff --git a/lib/classGenerator.js b/lib/classGenerator.js
index 2c450af..303fc34 100644
--- a/lib/classGenerator.js
+++ b/lib/classGenerator.js
@@ -6,6 +6,7 @@ const acceptChars = 'abcdefghijklmnopqrstuvwxyz_-0123456789'.split('');
 function ClassGenerator() {
     this.newClassMap = {};
     this.newClassSize = 0;
+    this.context = {}
 }
 
 function stripEscapeSequence(words) {
@@ -13,11 +14,7 @@ function stripEscapeSequence(words) {
 }
 
 ClassGenerator.prototype = {
-  generateClassName: function(original, opts) {
-    original = stripEscapeSequence(original);
-    const cn = this.newClassMap[original];
-    if (cn) return cn;
-
+  defaultClassGenerator: function() {
     const chars = []
     let rest = (this.newClassSize - (this.newClassSize % acceptPrefix.length)) / acceptPrefix.length
     if (rest > 0) {
@@ -36,6 +33,21 @@ ClassGenerator.prototype = {
     let prefixIndex = this.newClassSize % acceptPrefix.length
 
     const newClassName = `${acceptPrefix[prefixIndex]}${chars.join('')}`
+    return newClassName;
+  },
+  generateClassName: function(original, opts) {
+    original = stripEscapeSequence(original);
+    const cn = this.newClassMap[original];
+    if (cn) return cn;
+
+    let newClassName;
+    if (opts.classGenerator) {
+      newClassName = opts.classGenerator(original, opts, this.context);
+    }
+    if (!newClassName) {
+      newClassName = this.defaultClassGenerator();
+    }
+
     if (opts.reserveClassName && opts.reserveClassName.includes(newClassName)) {
       if (opts.log) {
         console.log(`The class name has been reserved. ${chalk.green(newClassName)}`);
diff --git a/lib/optimizer.js b/lib/optimizer.js
index 028c503..582adf4 100644
--- a/lib/optimizer.js
+++ b/lib/optimizer.js
@@ -2,9 +2,7 @@ const { ReplaceSource } = require('webpack-sources');
 const chalk = require('./chalk');
 const ClassGenerator = require('./classGenerator');
 
-const classGenerator = new ClassGenerator()
-
-const validate = (opts) => {
+const validate = (opts, classGenerator) => {
   if (!opts.log) return;
   for (let className in classGenerator.newClassMap) {
     const c = classGenerator.newClassMap[className];
@@ -19,7 +17,7 @@ const validate = (opts) => {
   }
 };
 
-const optimize = (chunk, compilation, opts) => chunk.files.forEach((file) => {
+const optimize = (chunk, compilation, opts, classGenerator) => chunk.files.forEach((file) => {
   let classnameRegex;
   if (file.match(/.+\.css.*$/)) {
     classnameRegex = new RegExp(`\\\.(${opts.classNameRegExp})`, 'g');
@@ -85,9 +83,9 @@ const optimize = (chunk, compilation, opts) => chunk.files.forEach((file) => {
 
 const optimizer = (compiler, compilation, opts) => (chunks) => {
   if (!opts.classNameRegExp) throw new Error("'classNameRegExp' option is required. e.g. '[c]-[a-z][a-zA-Z0-9_]*'");
-
-  chunks.forEach((chunk) => optimize(chunk, compilation, opts));
-  validate(opts);
+  const classGenerator = new ClassGenerator();
+  chunks.forEach((chunk) => optimize(chunk, compilation, opts, classGenerator));
+  validate(opts, classGenerator);
 }
 
 module.exports = optimizer;
diff --git a/spec/BasicSpec.js b/spec/BasicSpec.js
index b27461f..886067c 100644
--- a/spec/BasicSpec.js
+++ b/spec/BasicSpec.js
@@ -1,7 +1,7 @@
 var path = require('path');
 var fs = require('fs');
-var webpack = require('webpack');
 var rimraf = require('rimraf');
+var webpack = require('webpack');
 var webpackMajorVersion = Number(require('webpack/package.json').version.split('.')[0]);
 if (webpackMajorVersion < 4) {
   var CommonsChunkPlugin = require('webpack/lib/optimize/CommonsChunkPlugin');
@@ -197,4 +197,28 @@ describe('MangleCssClassPlugin', () => {
     expect(classNameWithEscape.name).toBe(classNameWithoutEscape.name);
     done();
   });
+
+  it('override class name generator', (done) => {
+    testPlugin({
+      entry: [path.join(__dirname, 'fixtures/case4.js')],
+      output: {
+        path: OUTPUT_DIR,
+        filename: 'case4.js',
+      },
+      plugins: [new MangleCssClassPlugin({
+        classNameRegExp: defaultCssClassRegExp,
+        log: true,
+        classGenerator: (original, opts, context) => {
+          if (!context.id) {
+            context.id = 1;
+          }
+          if (original.startsWith('c-')) {
+            const className = `c${context.id}`;
+            context.id++;
+            return className;
+          }
+        }
+      })]
+    }, ["<p class=\\\"c1\\\">hoge-a<div class=\\\"b c1\\\">CASE 4</div></p>"], done);
+  });
 });
diff --git a/spec/fixtures/case4.js b/spec/fixtures/case4.js
new file mode 100644
index 0000000..7334578
--- /dev/null
+++ b/spec/fixtures/case4.js
@@ -0,0 +1 @@
+const a = '<p class="c-a">hoge-a<div class="l-abc c-a">CASE 4</div></p>';
diff --git a/spec/support/jasmine.json b/spec/support/jasmine.json
index 54750e1..0b22611 100644
--- a/spec/support/jasmine.json
+++ b/spec/support/jasmine.json
@@ -3,6 +3,6 @@
   "spec_files": [
     "**/*[sS]pec.js"
   ],
-  "stopSpecOnExpectationFailure": false,
-  "random": true
+  "stopSpecOnExpectationFailure": true,
+  "random": false
 }