diff --git a/mozilla/browser/base/content/tabbrowser.xml b/mozilla/browser/base/content/tabbrowser.xml
index 4b72a050759..5726955d6dd 100644
--- a/mozilla/browser/base/content/tabbrowser.xml
+++ b/mozilla/browser/base/content/tabbrowser.xml
@@ -1257,7 +1257,10 @@
         <parameter name="aEvent"/>
         <body>
           <![CDATA[
-            if (aEvent.originalTarget.localName != 'tab' && aEvent.button == 0) {
+            if (aEvent.button == 0 && aEvent.originalTarget.localName != 'tab' &&
+                // Workaround to Bug 224002, the preventBubble() call in the tabbox binding
+                // should block this event.
+                aEvent.originalTarget.localName != "toolbarbutton") {
               var e = document.createEvent("Events");
               e.initEvent("NewTab", false, true);
               this.dispatchEvent(e);
