--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -2120,29 +2120,29 @@ DecodingState::Enter()
   }
 }
 
 void
 MediaDecoderStateMachine::
 DecodingState::HandleEndOfAudio()
 {
   AudioQueue().Finish();
-  if (mMaster->CheckIfDecodeComplete()) {
+  if (!mMaster->IsVideoDecoding()) {
     SetState<CompletedState>();
   } else {
     MaybeStopPrerolling();
   }
 }
 
 void
 MediaDecoderStateMachine::
 DecodingState::HandleEndOfVideo()
 {
   VideoQueue().Finish();
-  if (mMaster->CheckIfDecodeComplete()) {
+  if (!mMaster->IsAudioDecoding()) {
     SetState<CompletedState>();
   } else {
     MaybeStopPrerolling();
   }
 }
 
 void
 MediaDecoderStateMachine::
@@ -2376,30 +2376,30 @@ BufferingState::Step()
   SetState<DecodingState>();
 }
 
 void
 MediaDecoderStateMachine::
 BufferingState::HandleEndOfAudio()
 {
   AudioQueue().Finish();
-  if (mMaster->CheckIfDecodeComplete()) {
+  if (!mMaster->IsVideoDecoding()) {
     SetState<CompletedState>();
   } else {
     // Check if we can exit buffering.
     mMaster->ScheduleStateMachine();
   }
 }
 
 void
 MediaDecoderStateMachine::
 BufferingState::HandleEndOfVideo()
 {
   VideoQueue().Finish();
-  if (mMaster->CheckIfDecodeComplete()) {
+  if (!mMaster->IsAudioDecoding()) {
     SetState<CompletedState>();
   } else {
     // Check if we can exit buffering.
     mMaster->ScheduleStateMachine();
   }
 }
 
 RefPtr<ShutdownPromise>