diff --git a/browser/base/content/aboutDialog.xul b/browser/base/content/aboutDialog.xul
index 4b4fead14bfc..8c59074a48d2 100644
--- a/browser/base/content/aboutDialog.xul
+++ b/browser/base/content/aboutDialog.xul
@@ -57,6 +57,7 @@
         windowtype="Browser:About"
         onload="init(event);" onunload="uninit(event);"
 #ifdef XP_MACOSX
+        inwindowmenu="false"
         buttons="extra2"
         align="end"
 #else
diff --git a/toolkit/content/macWindowMenu.inc b/toolkit/content/macWindowMenu.inc
index 28d3fbba2494..c345ad8b7f35 100644
--- a/toolkit/content/macWindowMenu.inc
+++ b/toolkit/content/macWindowMenu.inc
@@ -16,7 +16,7 @@
     <menu id="windowMenu"
           label="&windowMenu.label;"
           datasources="rdf:window-mediator" ref="NC:WindowMediatorRoot"
-          onpopupshowing="checkFocusedWindow();"
+          onpopupshowing="macWindowMenuDidShow();"
           hidden="false">
         <template>
         <rule>
diff --git a/toolkit/content/macWindowMenu.js b/toolkit/content/macWindowMenu.js
index 997e946fa9c9..6032af22ee66 100644
--- a/toolkit/content/macWindowMenu.js
+++ b/toolkit/content/macWindowMenu.js
@@ -35,21 +35,20 @@
 # 
 # ***** END LICENSE BLOCK *****
 
-function checkFocusedWindow()
+function macWindowMenuDidShow()
 {
   var windowManagerDS =
     Components.classes['@mozilla.org/rdf/datasource;1?name=window-mediator']
               .getService(Components.interfaces.nsIWindowDataSource);
-
   var sep = document.getElementById("sep-window-list");
   // Using double parens to avoid warning
   while ((sep = sep.nextSibling)) {
     var url = sep.getAttribute('id');
     var win = windowManagerDS.getWindowForResource(url);
-    if (win == window) {
+    if (win.document.documentElement.getAttribute("inwindowmenu") == "false")
+      sep.hidden = true;
+    else if (win == window)
       sep.setAttribute("checked", "true");
-      break;
-    }
   }
 }