diff --git a/suite/common/nsContextMenu.js b/suite/common/nsContextMenu.js
index ecab584cd1e4..3f0f0122940a 100644
--- a/suite/common/nsContextMenu.js
+++ b/suite/common/nsContextMenu.js
@@ -889,7 +889,7 @@ function nsDefaultEngine()
         var pb = Components.classes["@mozilla.org/preferences-service;1"].
                    getService(Components.interfaces.nsIPrefBranch);
         var pbi = pb.QueryInterface(
-                    Components.interfaces.nsIPrefBranchInternal);
+                    Components.interfaces.nsIPrefBranch2);
         pbi.addObserver(this.domain, this, false);
 
         // reuse code by explicitly invoking initial |observe| call
diff --git a/suite/common/utilityOverlay.js b/suite/common/utilityOverlay.js
index 3b6a6f8ee20e..6d7c6d3b5f4b 100644
--- a/suite/common/utilityOverlay.js
+++ b/suite/common/utilityOverlay.js
@@ -515,7 +515,7 @@ function utilityOnLoad(aEvent)
   var prefService = Components.classes["@mozilla.org/preferences-service;1"];
   prefService = prefService.getService(Components.interfaces.nsIPrefService);
   var prefBranch = prefService.getBranch(null);
-  prefBranch = prefBranch.QueryInterface(Components.interfaces.nsIPrefBranchInternal);
+  prefBranch = prefBranch.QueryInterface(Components.interfaces.nsIPrefBranch2);
 
   prefBranch.addObserver("network.proxy.type", proxyTypeObserver, false);
 
@@ -535,7 +535,7 @@ function utilityOnUnload(aEvent)
   var prefService = Components.classes["@mozilla.org/preferences-service;1"];
   prefService = prefService.getService(Components.interfaces.nsIPrefService);
   var prefBranch = prefService.getBranch(null);
-  prefBranch = prefBranch.QueryInterface(Components.interfaces.nsIPrefBranchInternal);
+  prefBranch = prefBranch.QueryInterface(Components.interfaces.nsIPrefBranch2);
   
   prefBranch.removeObserver("network.proxy.type", proxyTypeObserver);
 }