--- a/toolkit/content/widgets/tabbox.xml
+++ b/toolkit/content/widgets/tabbox.xml
@@ -181,44 +181,36 @@
       </method>
 
       <field name="_eventNode">this</field>
 
       <property name="eventNode" onget="return this._eventNode;">
         <setter>
           <![CDATA[
             if (val != this._eventNode) {
-              const nsIEventListenerService =
-                Ci.nsIEventListenerService;
-              let els = Cc["@mozilla.org/eventlistenerservice;1"]
-                          .getService(nsIEventListenerService);
-              els.addSystemEventListener(val, "keydown", this, false);
-              els.removeSystemEventListener(this._eventNode, "keydown", this, false);
+              Services.els.addSystemEventListener(val, "keydown", this, false);
+              Services.els.removeSystemEventListener(this._eventNode, "keydown", this, false);
               this._eventNode = val;
             }
             return val;
           ]]>
         </setter>
       </property>
 
       <constructor>
         switch (this.getAttribute("eventnode")) {
           case "parent": this._eventNode = this.parentNode; break;
           case "window": this._eventNode = window; break;
           case "document": this._eventNode = document; break;
         }
-        let els = Cc["@mozilla.org/eventlistenerservice;1"]
-                    .getService(Ci.nsIEventListenerService);
-        els.addSystemEventListener(this._eventNode, "keydown", this, false);
+        Services.els.addSystemEventListener(this._eventNode, "keydown", this, false);
       </constructor>
 
       <destructor>
-        let els = Cc["@mozilla.org/eventlistenerservice;1"]
-                    .getService(Ci.nsIEventListenerService);
-        els.removeSystemEventListener(this._eventNode, "keydown", this, false);
+        Services.els.removeSystemEventListener(this._eventNode, "keydown", this, false);
       </destructor>
     </implementation>
   </binding>
 
   <binding id="tabs"
            extends="chrome://global/content/bindings/general.xml#basecontrol">
     <resources>
       <stylesheet src="chrome://global/skin/tabbox.css"/>