diff --git a/test/browserstack.js b/test/browserstack.js
index bb641a8c..75017f4f 100644
--- a/test/browserstack.js
+++ b/test/browserstack.js
@@ -1,6 +1,7 @@
 define([
   './intern',
-], function(config) {
+  'intern/dojo/text!./config/firefox-profile.webcomponents.txt',
+], function(config, firefoxProfileWebcomponents) {
 
   config.capabilities = {
     project: 'ally.js',
@@ -32,6 +33,17 @@ define([
     { browser: 'Firefox', browser_version: '42', os: 'OS X', os_version: 'Yosemite', platform: 'MAC', browserName: 'Firefox 42' },
     { browser: 'Chrome', browser_version: '47', os: 'OS X', os_version: 'Yosemite', platform: 'MAC', browserName: 'Chrome 47' },
 
+    {
+      browser: 'Firefox',
+      browser_version: '42',
+      os: 'WINDOWS',
+      os_version: '8.1',
+      platform: 'WIN',
+      browserName: 'Firefox 42 (ShadowDOM)',
+      // dom.webcomponents.enabled=true
+      firefox_profile: firefoxProfileWebcomponents,
+    },
+
     { browser: 'Safari', browser_version: '9.0', os: 'OS X', os_version: 'El Capitan', platform: 'MAC', browserName: 'Safari 9' },
     { browser: 'Safari', browser_version: '8', os: 'OS X', os_version: 'Yosemite', platform: 'MAC', browserName: 'Safari 8' },
     { browser: 'Safari', browser_version: '7.1', os: 'OS X', os_version: 'Mavericks', platform: 'MAC', browserName: 'Safari 7' },
diff --git a/test/config/README.md b/test/config/README.md
new file mode 100644
index 00000000..f16a1701
--- /dev/null
+++ b/test/config/README.md
@@ -0,0 +1,21 @@
+# Generating Firefox Profiles
+
+It is possible to configure Firefox instance, e.g. to enable ShadowDOM support. [firefox-profile](https://www.npmjs.com/package/firefox-profile) can generate base64 encoded profiles including preferences and extensions.
+
+The generated profile can be passed to an environment entry for Firefox via the `firefox_profile` capability.
+
+---
+
+```sh
+npm install firefox-profile
+```
+
+```js
+var FirefoxProfile = require('firefox-profile');
+var profile = new FirefoxProfile();
+profile.setPreference('dom.webcomponents.enabled', true);
+profile.updatePreferences();
+profile.encoded(function(data) {
+  console.log(data);
+});
+```
diff --git a/test/config/firefox-profile.webcomponents.txt b/test/config/firefox-profile.webcomponents.txt
new file mode 100644
index 00000000..e0a4e8b3
--- /dev/null
+++ b/test/config/firefox-profile.webcomponents.txt
@@ -0,0 +1 @@
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
\ No newline at end of file