diff --git a/dom/tests/mochitest/general/test_interfaces.html b/dom/tests/mochitest/general/test_interfaces.html
index 3c4f753423fb..86328f50935a 100644
--- a/dom/tests/mochitest/general/test_interfaces.html
+++ b/dom/tests/mochitest/general/test_interfaces.html
@@ -140,7 +140,7 @@ var interfaceNamesInGlobalScope =
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "AnimationEvent",
 // IMPORTANT: Do not change this list without review from a DOM peer!
-    "AnimationPlaybackEvent",
+    {name: "AnimationPlaybackEvent", release: false},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     {name: "AnimationTimeline", release: false},
 // IMPORTANT: Do not change this list without review from a DOM peer!