diff --git a/docs/index.md b/docs/index.md
index caf29ab..64a9bea 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -8,7 +8,7 @@ See complete examples in [full examples](#full-examples) section.
 You can include ES6 polyfills by adding to your index.html:
 
 ```
-<script crossorigin="anonymous" src="https://polyfill.io/v3/polyfill.min.js"></script>
+<script crossorigin="anonymous" src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 ```
 
 See https://github.com/jeremyckahn/shifty#ie-compatibility and https://polyfill.io/v3/url-builder/.
diff --git a/karma.conf.js b/karma.conf.js
index b4128b6..96dbd0f 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -2,8 +2,8 @@ var customLaunchers = require('./saucelabs-browsers');
 
 module.exports = function(config) {
     config.set({
-        frameworks: ['mocha', 'browserify'],
-
+        frameworks: ['polyfill', 'mocha', 'browserify'],
+        polyfill: ['es6'],
         files: [
           'test/*.js'
         ],
diff --git a/package-lock.json b/package-lock.json
index b12de99..33bb382 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -6820,6 +6820,12 @@
         "minimist": "1.2.0"
       }
     },
+    "karma-polyfill": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/karma-polyfill/-/karma-polyfill-1.1.0.tgz",
+      "integrity": "sha512-TGWOIeTa4VBU2Af6jp4IYbROlTH6EXqpQZt15r0TRv7AYMt03BIagj5eljZgC64Uqg11QDh09j9megr6Vmzm6g==",
+      "dev": true
+    },
     "karma-sauce-launcher": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/karma-sauce-launcher/-/karma-sauce-launcher-1.2.0.tgz",
diff --git a/package.json b/package.json
index 2fa6edb..96a4252 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
     "karma": "^2.0.2",
     "karma-browserify": "^5.2.0",
     "karma-mocha": "^1.3.0",
+    "karma-polyfill": "^1.1.0",
     "karma-sauce-launcher": "^1.2.0",
     "lodash": "^2.4.1",
     "mocha": "^2.0.1",
diff --git a/test/testem.html b/test/testem.html
index 3fd6ccf..2eac90b 100644
--- a/test/testem.html
+++ b/test/testem.html
@@ -18,6 +18,7 @@ <h1>Test div</h1>
             <div id="container"></div>
         </div>
 
+        <script crossorigin="anonymous" src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
         <script src="/node_modules/mocha/mocha.js"></script>
         <script>mocha.setup('bdd')</script>
         <script src="/testem.js"></script>