diff --git a/performance-timeline/navigation-id-worker-created-entries.html b/performance-timeline/navigation-id-worker-created-entries.html
index 96fc57be1d426c..5c41ee8b86b530 100644
--- a/performance-timeline/navigation-id-worker-created-entries.html
+++ b/performance-timeline/navigation-id-worker-created-entries.html
@@ -18,9 +18,8 @@
         worker.postMessage('');
       });
 
-      assert_equals(navigationId.length, 0,
-        'Navigation id of performance entries created by a worker should be empty.');
-    }, 'Navigation id of performance entries created by workers should be empty');
+      assert_equals(navigationId, 0, '0 indicates the absence of a navigation id.');
+    }, 'Navigation id of performance entries created by workers should be 0.');
   </script>
 </body>