diff --git a/testing/web-platform/meta/workers/interfaces/DedicatedWorkerGlobalScope/postMessage/message-event.html.ini b/testing/web-platform/meta/workers/interfaces/DedicatedWorkerGlobalScope/postMessage/message-event.html.ini
index c810dcf32ed..a0894311c6e 100644
--- a/testing/web-platform/meta/workers/interfaces/DedicatedWorkerGlobalScope/postMessage/message-event.html.ini
+++ b/testing/web-platform/meta/workers/interfaces/DedicatedWorkerGlobalScope/postMessage/message-event.html.ini
@@ -2,4 +2,5 @@
   type: testharness
   [Properties of the 'message' event]
     expected: FAIL
+    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1164834