--- a/browser/components/extensions/test/browser/browser_ext_devtools_panel.js
+++ b/browser/components/extensions/test/browser/browser_ext_devtools_panel.js
@@ -281,17 +281,17 @@ add_task(async function test_devtools_pa
   Services.prefs.setBoolPref(`devtools.webext-${panelId}.enabled`, false);
   gDevTools.emit("tool-unregistered", panelId);
 
   await waitToolVisibilityOff;
 
   ok(toolbox.hasAdditionalTool(panelId),
      "The tool has not been removed on visibilityswitch set to false");
 
-  is(toolbox.visibleAdditionalTools.filter(tool => tool.id == panelId).length, 0,
+  is(toolbox.visibleAdditionalTools.filter(toolId => toolId == panelId).length, 0,
      "The tool is not visible on visibilityswitch set to false");
 
   // Turn on the addon devtools panel using the visibilityswitch.
   const waitToolVisibilityOn = toolbox.once("tool-registered");
 
   Services.prefs.setBoolPref(`devtools.webext-${panelId}.enabled`, true);
   gDevTools.emit("tool-registered", panelId);