--- a/devtools/client/shared/widgets/HTMLTooltip.js
+++ b/devtools/client/shared/widgets/HTMLTooltip.js
@@ -568,16 +568,17 @@ HTMLTooltip.prototype = {
     let panel = this.doc.createElementNS(XUL_NS, "panel");
 
     // XUL panel is only a way to display DOM elements outside of the document viewport,
     // so disable all features that impact the behavior.
     panel.setAttribute("animate", false);
     panel.setAttribute("consumeoutsideclicks", false);
     panel.setAttribute("noautofocus", true);
     panel.setAttribute("ignorekeys", true);
+    panel.setAttribute("tooltip", "aHTMLTooltip");
 
     // Use type="arrow" to prevent side effects (see Bug 1285206)
     panel.setAttribute("type", "arrow");
 
     panel.setAttribute("level", "top");
     panel.setAttribute("class", "tooltip-xul-wrapper");
 
     return panel;