diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index a2c67ed8504..f445f232ebe 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -4640,8 +4640,15 @@ var TabsOnTop = {
 
 #ifdef MENUBAR_CAN_AUTOHIDE
 function updateAppButtonDisplay() {
-  document.getElementById("appmenu-button-container").hidden =
-    document.getElementById("toolbar-menubar").getAttribute("autohide") != "true";
+  var menubarHidden =
+    document.getElementById("toolbar-menubar").getAttribute("autohide") == "true";
+
+  document.getElementById("appmenu-button-container").hidden = !menubarHidden;
+
+  if (menubarHidden)
+    document.documentElement.setAttribute("chromemargin", "0,-1,-1,-1");
+  else
+    document.documentElement.removeAttribute("chromemargin");
 }
 #endif
 
diff --git a/browser/base/content/win6BrowserOverlay.xul b/browser/base/content/win6BrowserOverlay.xul
new file mode 100644
index 00000000000..c2dbaf3fb34
--- /dev/null
+++ b/browser/base/content/win6BrowserOverlay.xul
@@ -0,0 +1,44 @@
+<?xml version="1.0"?>
+# -*- Mode: HTML -*-
+#
+# ***** BEGIN LICENSE BLOCK *****
+# Version: MPL 1.1/GPL 2.0/LGPL 2.1
+#
+# The contents of this file are subject to the Mozilla Public License Version
+# 1.1 (the "License"); you may not use this file except in compliance with
+# the License. You may obtain a copy of the License at
+# http://www.mozilla.org/MPL/
+#
+# Software distributed under the License is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+# for the specific language governing rights and limitations under the
+# License.
+#
+# The Original Code is mozilla.org Code.
+#
+# The Initial Developer of the Original Code is the Mozilla Foundation.
+# Portions created by the Initial Developer are Copyright (C) 2010
+# the Initial Developer. All Rights Reserved.
+#
+# Contributor(s):
+#   Dão Gottwald <dao@mozilla.com> (Original Author)
+#
+# Alternatively, the contents of this file may be used under the terms of
+# either the GNU General Public License Version 2 or later (the "GPL"), or
+# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+# in which case the provisions of the GPL or the LGPL are applicable instead
+# of those above. If you wish to allow use of your version of this file only
+# under the terms of either the GPL or the LGPL, and not to allow others to
+# use your version of this file under the terms of the MPL, indicate your
+# decision by deleting the provisions above and replace them with the notice
+# and other provisions required by the GPL or the LGPL. If you do not delete
+# the provisions above, a recipient may use your version of this file under
+# the terms of any one of the MPL, the GPL or the LGPL.
+#
+# ***** END LICENSE BLOCK *****
+
+<overlay id="win6-browser-overlay"
+         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+  <toolbar id="toolbar-menubar"
+           autohide="true"/>
+</overlay>
diff --git a/browser/base/jar.mn b/browser/base/jar.mn
index 6b1051af84d..21fdaa9cca8 100644
--- a/browser/base/jar.mn
+++ b/browser/base/jar.mn
@@ -6,6 +6,9 @@ browser.jar:
 %  overlay chrome://global/content/console.xul chrome://browser/content/jsConsoleOverlay.xul
 %  overlay chrome://mozapps/content/update/updates.xul chrome://browser/content/softwareUpdateOverlay.xul
 #endif
+#ifdef XP_WIN
+%  overlay chrome://browser/content/browser.xul chrome://browser/content/win6BrowserOverlay.xul os=WINNT osversion>=6
+#endif
 %  overlay chrome://global/content/viewSource.xul chrome://browser/content/viewSourceOverlay.xul
 %  overlay chrome://global/content/viewPartialSource.xul chrome://browser/content/viewSourceOverlay.xul
 %  style chrome://global/content/customizeToolbar.xul chrome://browser/content/browser.css
@@ -59,6 +62,9 @@ browser.jar:
 *       content/browser/softwareUpdateOverlay.xul  (content/softwareUpdateOverlay.xul)
 #endif
 *       content/browser/viewSourceOverlay.xul         (content/viewSourceOverlay.xul)
+#ifdef XP_WIN
+*       content/browser/win6BrowserOverlay.xul        (content/win6BrowserOverlay.xul)
+#endif
 # the following files are browser-specific overrides
 *       content/browser/license.html                  (/toolkit/content/license.html)
 % override chrome://global/content/license.html chrome://browser/content/license.html