diff --git a/mozilla/xpfe/components/sidebar/resources/sidebarOverlay.xul b/mozilla/xpfe/components/sidebar/resources/sidebarOverlay.xul
index 70178022986..d342d7564f9 100644
--- a/mozilla/xpfe/components/sidebar/resources/sidebarOverlay.xul
+++ b/mozilla/xpfe/components/sidebar/resources/sidebarOverlay.xul
@@ -150,9 +150,9 @@
                   </hbox>
                   <spacer flex="100%"/>
                 </vbox>
-                <browser class="iframe-panel" flex="1*" src="about:blank"
+                <browser flex="1*" src="about:blank"
                   hidden="true" collapsed="true" content="?content"/>
-                <browser class="iframe-panel" flex="1*" src="about:blank"
+                <browser flex="1*" src="about:blank"
                   hidden="true" collapsed="true" content="?content" type="content" context="contentAreaContextMenu"/>
               </vbox>
             </action>