--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -977,17 +977,16 @@
       </hbox>
 
       <toolbarbutton id="nav-bar-overflow-button"
                      class="toolbarbutton-1 chromeclass-toolbar-additional overflow-button"
                      skipintoolbarset="true"
                      tooltiptext="&navbarOverflow.label;"/>
 
       <toolbaritem id="PanelUI-button"
-                   class="chromeclass-toolbar-additional"
                    removable="false">
         <toolbarbutton id="PanelUI-menu-button"
                        class="toolbarbutton-1"
                        consumeanchor="PanelUI-button"
                        label="&brandShortName;"
                        tooltiptext="&appmenu.tooltip;"/>
       </toolbaritem>
 

--- a/toolkit/content/xul.css
+++ b/toolkit/content/xul.css
@@ -29,17 +29,17 @@
    ::::: */
 
 window[chromehidden~="menubar"] .chromeclass-menubar,
 window[chromehidden~="directories"] .chromeclass-directories,
 window[chromehidden~="status"] .chromeclass-status,
 window[chromehidden~="extrachrome"] .chromeclass-extrachrome,
 window[chromehidden~="location"] .chromeclass-location,
 window[chromehidden~="location"][chromehidden~="toolbar"] .chromeclass-toolbar,
-window[chromehidden~="toolbar"] .chromeclass-toolbar-additional {
+window[chromehidden~="toolbar"] toolbar .chromeclass-toolbar-additional {
   display: none;
 }
 
 /* ::::::::::
    :: Rules for forcing direction for entry and display of URIs
    :: or URI elements
    ::::: */