diff --git a/browser/base/content/browser-menubar.inc b/browser/base/content/browser-menubar.inc
index a27a1d5aedc2..502f21983924 100644
--- a/browser/base/content/browser-menubar.inc
+++ b/browser/base/content/browser-menubar.inc
@@ -212,6 +212,7 @@
                               observes="viewHistorySidebar"
                               label="&historyButton.label;"/>
                     <menuitem id="menu_tabsSidebar"
+                              class="sync-ui-item"
                               observes="viewTabsSidebar"
                               label="&syncedTabs.sidebar.label;"/>
                   </menupopup>
diff --git a/browser/base/content/browser.xul b/browser/base/content/browser.xul
index 23765eef43ac..b84e36c6e95e 100644
--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -298,7 +298,7 @@
       </toolbarbutton>
       <toolbarbutton id="sidebar-switcher-tabs"
                      label="&syncedTabs.sidebar.label;"
-                     class="subviewbutton subviewbutton-iconic"
+                     class="subviewbutton subviewbutton-iconic sync-ui-item"
                      observes="viewTabsSidebar"
                      oncommand="SidebarUI.show('viewTabsSidebar');">
         <observes element="viewTabsSidebar" attribute="checked"/>