--- a/toolkit/content/widgets/browser.xml
+++ b/toolkit/content/widgets/browser.xml
@@ -3,17 +3,17 @@
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <bindings id="browserBindings"
           xmlns="http://www.mozilla.org/xbl"
           xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
 
-  <binding id="browser" extends="xul:browser">
+  <binding id="browser">
     <content clickthrough="never">
       <children/>
     </content>
     <implementation type="application/javascript" implements="nsIObserver, nsIDOMEventListener, nsIMessageListener, nsIBrowser">
       <property name="autoscrollEnabled">
         <getter>
           <![CDATA[
             if (this.getAttribute("autoscroll") == "false")