--- a/dom/media/TextTrack.cpp
+++ b/dom/media/TextTrack.cpp
@@ -8,16 +8,17 @@
 #include "mozilla/dom/TextTrack.h"
 #include "mozilla/dom/TextTrackBinding.h"
 #include "mozilla/dom/TextTrackList.h"
 #include "mozilla/dom/TextTrackCue.h"
 #include "mozilla/dom/TextTrackCueList.h"
 #include "mozilla/dom/TextTrackRegion.h"
 #include "mozilla/dom/HTMLMediaElement.h"
 #include "mozilla/dom/HTMLTrackElement.h"
+#include "nsGlobalWindow.h"
 
 namespace mozilla {
 namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_INHERITED(TextTrack,
                                    DOMEventTargetHelper,
                                    mCueList,
                                    mActiveCueList,
@@ -325,18 +326,23 @@ TextTrack::GetLanguage(nsAString& aLangu
   } else {
     aLanguage = mLanguage;
   }
 }
 
 void
 TextTrack::DispatchAsyncTrustedEvent(const nsString& aEventName)
 {
+  nsPIDOMWindowInner* win = GetOwner();
+  if (!win) {
+    return;
+  }
   RefPtr<TextTrack> self = this;
-  NS_DispatchToMainThread(
+  nsGlobalWindow::Cast(win)->Dispatch(
+    "TextTrack::DispatchAsyncTrustedEvent", TaskCategory::Other,
     NS_NewRunnableFunction([self, aEventName]() {
       self->DispatchTrustedEvent(aEventName);
     })
   );
 }
 
 bool
 TextTrack::IsLoaded()