diff --git a/browser/components/customizableui/content/panelUI.js b/browser/components/customizableui/content/panelUI.js
index 7d221b2d952..d555a0c039e 100644
--- a/browser/components/customizableui/content/panelUI.js
+++ b/browser/components/customizableui/content/panelUI.js
@@ -180,6 +180,7 @@ const PanelUI = {
       let tempPanel = document.createElement("panel");
       tempPanel.setAttribute("type", "arrow");
       tempPanel.setAttribute("id", "customizationui-widget-panel");
+      tempPanel.setAttribute("level", "top");
       document.getElementById(CustomizableUI.AREA_NAVBAR).appendChild(tempPanel);
 
       let multiView = document.createElement("panelmultiview");