--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -948,16 +948,21 @@ public:
     return MediaDecoder::SeekPromise::CreateAndReject(true, __func__);
   }
 
   RefPtr<ShutdownPromise> HandleShutdown() override
   {
     MOZ_DIAGNOSTIC_ASSERT(false, "Already shutting down.");
     return nullptr;
   }
+
+  void HandleVideoSuspendTimeout() override
+  {
+    MOZ_DIAGNOSTIC_ASSERT(false, "Already shutting down.");
+  }
 };
 
 bool
 MediaDecoderStateMachine::
 StateObject::HandleDormant(bool aDormant)
 {
   if (!aDormant) {
     return true;