--- a/dom/media/platforms/PDMFactory.cpp
+++ b/dom/media/platforms/PDMFactory.cpp
@@ -262,17 +262,17 @@ PDMFactory::CreateDecoderWithPDM(Platfor
       TimeDuration::FromMilliseconds(MediaPrefs::PDMFuzzingInterval()));
     callbackWrapper->SetDontDelayInputExhausted(!MediaPrefs::PDMFuzzingDelayInputExhausted());
     callback = callbackWrapper.get();
   }
 
   CreateDecoderParams params = aParams;
   params.mCallback = callback;
 
-  if (MP4Decoder::IsH264(config.mMimeType)) {
+  if (MP4Decoder::IsH264(config.mMimeType) && !aParams.mUseBlankDecoder) {
     RefPtr<H264Converter> h = new H264Converter(aPDM, params);
     const nsresult rv = h->GetLastError();
     if (NS_SUCCEEDED(rv) || rv == NS_ERROR_NOT_INITIALIZED) {
       // The H264Converter either successfully created the wrapped decoder,
       // or there wasn't enough AVCC data to do so. Otherwise, there was some
       // problem, for example WMF DLLs were missing.
       m = h.forget();
     }