--- a/browser/components/customizableui/PanelMultiView.jsm
+++ b/browser/components/customizableui/PanelMultiView.jsm
@@ -874,17 +874,17 @@ this.PanelMultiView = class {
       case "popupshowing":
         this.node.setAttribute("panelopen", "true");
         // Bug 941196 - The panel can get taller when opening a subview. Disabling
         // autoPositioning means that the panel won't jump around if an opened
         // subview causes the panel to exceed the dimensions of the screen in the
         // direction that the panel originally opened in. This property resets
         // every time the popup closes, which is why we have to set it each time.
         this._panel.autoPosition = false;
-        if (this.panelViews) {
+        if (this.panelViews && !this.node.hasAttribute("disablekeynav")) {
           this.window.addEventListener("keydown", this);
           this._panel.addEventListener("mousemove", this);
         }
 
         // Before opening the panel, we have to limit the maximum height of any
         // view based on the space that will be available. We cannot just use
         // window.screen.availTop and availHeight because these may return an
         // incorrect value when the window spans multiple screens.

--- a/browser/components/customizableui/content/panelUI.inc.xul
+++ b/browser/components/customizableui/content/panelUI.inc.xul
@@ -327,17 +327,17 @@
 
 <panel id="widget-overflow"
        role="group"
        type="arrow"
        noautofocus="true"
        position="bottomcenter topright"
        photon="true"
        hidden="true">
-  <photonpanelmultiview mainViewId="widget-overflow-mainView">
+  <photonpanelmultiview mainViewId="widget-overflow-mainView" disablekeynav="true">
     <panelview id="widget-overflow-mainView"
                context="toolbar-context-menu">
       <vbox class="panel-subview-body">
         <vbox id="widget-overflow-list" class="widget-overflow-list"
               overflowfortoolbar="nav-bar"/>
         <toolbarseparator id="widget-overflow-fixed-separator" hidden="true"/>
         <vbox id="widget-overflow-fixed-list" class="widget-overflow-list" hidden="true"
               emptylabel="&customizeMode.emptyOverflowList.description;"/>