diff --git a/toolkit/content/widgets/panel.js b/toolkit/content/widgets/panel.js
index 1dd4fc2a839fc6fde1ce2fc6437625e8d22bbb90..04fcb049225148f1b1f9c4b16cf2d2537887fbec 100644
--- a/toolkit/content/widgets/panel.js
+++ b/toolkit/content/widgets/panel.js
@@ -138,6 +138,9 @@
             this.anchorNode.closest("toolbarbutton, .anchor-root") ||
             this.anchorNode;
           anchorRoot.setAttribute("open", "true");
+          if (anchorRoot.closest("#urlbar") && window.gURLBar) {
+            gURLBar.setAttribute("has-popup-open", "true");
+          }
         }
 
         if (this.getAttribute("animate") != "false") {
@@ -208,6 +211,9 @@
             this.anchorNode.closest("toolbarbutton, .anchor-root") ||
             this.anchorNode;
           anchorRoot.removeAttribute("open");
+          if (anchorRoot.closest("#urlbar") && window.gURLBar) {
+            gURLBar.removeAttribute("has-popup-open");
+          }
         }
       }