--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -1223,24 +1223,20 @@ private:
       OnSeekTaskResolved();
     }
   }
 
   void OnSeekTaskResolved()
   {
     if (mSeekedAudioData) {
       mMaster->Push(mSeekedAudioData);
-      mMaster->mDecodedAudioEndTime = std::max(
-        mSeekedAudioData->GetEndTime(), mMaster->mDecodedAudioEndTime);
     }
 
     if (mSeekedVideoData) {
       mMaster->Push(mSeekedVideoData);
-      mMaster->mDecodedVideoEndTime = std::max(
-        mSeekedVideoData->GetEndTime(), mMaster->mDecodedVideoEndTime);
     }
 
     SeekCompleted();
   }
 
   void OnSeekTaskRejected(const MediaResult& aError)
   {
     mMaster->DecodeError(aError);