--- a/extension/content/browser.js
+++ b/extension/content/browser.js
@@ -147,17 +147,17 @@ var TestPilotMenuUtils;
   var TestPilotWindowHandlers = {
     onWindowLoad: function() {
       /* "Hold" window load events for TestPilotSetup, passing them along only
        * after startup is complete.  It's hacky, but the benefit is that
        * TestPilotSetup.onWindowLoad can treat all windows the same no matter
        * whether they opened with Firefox on startup or were opened later. */
       TestPilotWindowHandlers.setUpToolbarFeedbackButton();
 
-      if (TestPilotSetup.startupComplete) {
+      if (TestPilotSetup && TestPilotSetup.startupComplete) {
         TestPilotSetup.onWindowLoad(window);
       } else {
         let observerSvc = Cc["@mozilla.org/observer-service;1"]
                              .getService(Ci.nsIObserverService);
         let observer = {
           observe: function(subject, topic, data) {
             observerSvc.removeObserver(this, "testpilot:startup:complete");
             TestPilotSetup.onWindowLoad(window);