--- a/dom/media/AccurateSeekTask.cpp
+++ b/dom/media/AccurateSeekTask.cpp
@@ -428,18 +428,16 @@ AccurateSeekTask::OnAudioNotDecoded(Medi
     // If this is a decode error, delegate to the generic error path.
     RejectIfExist(__func__);
     return;
   }
 
   // If the decoder is waiting for data, we tell it to call us back when the
   // data arrives.
   if (aReason == MediaDecoderReader::WAITING_FOR_DATA) {
-    MOZ_ASSERT(mReader->IsWaitForDataSupported(),
-               "Readers that send WAITING_FOR_DATA need to implement WaitForData");
     mReader->WaitForData(MediaData::AUDIO_DATA);
     return;
   }
 
   if (aReason == MediaDecoderReader::CANCELED) {
     EnsureAudioDecodeTaskQueued();
     return;
   }
@@ -514,18 +512,16 @@ AccurateSeekTask::OnVideoNotDecoded(Medi
     // If this is a decode error, delegate to the generic error path.
     RejectIfExist(__func__);
     return;
   }
 
   // If the decoder is waiting for data, we tell it to call us back when the
   // data arrives.
   if (aReason == MediaDecoderReader::WAITING_FOR_DATA) {
-    MOZ_ASSERT(mReader->IsWaitForDataSupported(),
-               "Readers that send WAITING_FOR_DATA need to implement WaitForData");
     mReader->WaitForData(MediaData::VIDEO_DATA);
     return;
   }
 
   if (aReason == MediaDecoderReader::CANCELED) {
     EnsureVideoDecodeTaskQueued();
     return;
   }