diff --git a/toolkit/mozapps/extensions/content/extensions.xul b/toolkit/mozapps/extensions/content/extensions.xul
index 3af3408e5218..64cfd26d21dd 100644
--- a/toolkit/mozapps/extensions/content/extensions.xul
+++ b/toolkit/mozapps/extensions/content/extensions.xul
@@ -49,7 +49,7 @@
 <page xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
       xmlns:xhtml="http://www.w3.org/1999/xhtml"
       id="addons-page" title="&addons.windowTitle;" disablechrome="true"
-      role="application"
+      role="application" windowtype="Addons:Manager"
       ondragenter="gDragDrop.onDragOver(event)"
       ondragover="gDragDrop.onDragOver(event)"
       ondrop="gDragDrop.onDrop(event)">
diff --git a/toolkit/mozapps/extensions/test/browser/browser_bug562890.js b/toolkit/mozapps/extensions/test/browser/browser_bug562890.js
index 55d7a678bfb0..c81423bac7cc 100644
--- a/toolkit/mozapps/extensions/test/browser/browser_bug562890.js
+++ b/toolkit/mozapps/extensions/test/browser/browser_bug562890.js
@@ -24,15 +24,15 @@ function test() {
     optionsURL: addonPrefsURI
   }]);
   
-  open_manager("addons://list/extension", function(aWindow) {
-    var addonList = aWindow.document.getElementById("addon-list");
+  open_manager("addons://list/extension", function(aManager) {
+    var addonList = aManager.document.getElementById("addon-list");
     for (var i = 0; i < addonList.childNodes.length; i++) {
       var addonItem = addonList.childNodes[i];
       if (addonItem.hasAttribute("name") &&
           addonItem.getAttribute("name") == "Test add-on 1")
         break;
     }
-    var prefsBtn = aWindow.document.getAnonymousElementByAttribute(addonItem,
+    var prefsBtn = aManager.document.getAnonymousElementByAttribute(addonItem,
                                                                    "anonid",
                                                                    "preferences-btn");
     is(prefsBtn.hidden, true, "Prefs button should be hidden for addon with no optionsURL set")
@@ -43,26 +43,28 @@ function test() {
           addonItem.getAttribute("name") == "Test add-on 2")
         break;
     }
-    prefsBtn = aWindow.document.getAnonymousElementByAttribute(addonItem,
-                                                               "anonid",
-                                                               "preferences-btn");
+    prefsBtn = aManager.document.getAnonymousElementByAttribute(addonItem,
+                                                                "anonid",
+                                                                "preferences-btn");
     is(prefsBtn.hidden, false, "Prefs button should be shown for addon with a optionsURL set")
 
     Services.ww.registerNotification(function(aSubject, aTopic, aData) {
       if (aTopic == "domwindowclosed") {
         Services.ww.unregisterNotification(arguments.callee);
+        waitForFocus(function() {
+          close_manager(aManager);
+          finish();
+        }, aManager);
       } else if (aTopic == "domwindowopened") {
         let win = aSubject.QueryInterface(Ci.nsIDOMEventTarget);
         win.documentURI, addonPrefsURI, "The correct addon pref window should open"
         waitForFocus(function() {
           win.close();
-          aWindow.close();
-          finish();
         }, win);
       }
     });
 
-    EventUtils.synthesizeMouseAtCenter(prefsBtn, { }, aWindow);
+    EventUtils.synthesizeMouseAtCenter(prefsBtn, { }, aManager);
   });
 
 }
diff --git a/toolkit/mozapps/extensions/test/browser/head.js b/toolkit/mozapps/extensions/test/browser/head.js
index 78827a7bc325..7208d31f7e8f 100644
--- a/toolkit/mozapps/extensions/test/browser/head.js
+++ b/toolkit/mozapps/extensions/test/browser/head.js
@@ -45,6 +45,13 @@ registerCleanupFunction(function() {
   catch (e) {
   }
 
+  // Throw an error if the add-ons manager window is open anywhere
+  var windows = Services.wm.getEnumerator("Addons:Manager");
+  if (windows.hasMoreElements())
+    ok(false, "Found unexpected add-ons manager window still open");
+  while (windows.hasMoreElements())
+    windows.getNext().QueryInterface(Ci.nsIDOMWindow).close();
+
   // We can for now know that getAllInstalls actually calls its callback before
   // it returns so this will complete before the next test start.
   AddonManager.getAllInstalls(function(aInstalls) {