--- a/dom/media/platforms/agnostic/gmp/GMPAudioDecoder.cpp
+++ b/dom/media/platforms/agnostic/gmp/GMPAudioDecoder.cpp
@@ -118,18 +118,20 @@ AudioCallbackAdapter::ResetComplete()
   mMustRecaptureAudioPosition = true;
   mCallback->FlushComplete();
 }
 
 void
 AudioCallbackAdapter::Error(GMPErr aErr)
 {
   MOZ_ASSERT(IsOnGMPThread());
-  mCallback->Error(
-    MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR, RESULT_DETAIL("GMPErr:%x", aErr)));
+  mCallback->Error(MediaResult(aErr == GMPDecodeErr
+                               ? NS_ERROR_DOM_MEDIA_DECODE_ERR
+                               : NS_ERROR_DOM_MEDIA_FATAL_ERR,
+                               RESULT_DETAIL("GMPErr:%x", aErr)));
 }
 
 void
 AudioCallbackAdapter::Terminated()
 {
   mCallback->Error(MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
                                RESULT_DETAIL("Audio GMP decoder terminated.")));
 }

--- a/dom/media/platforms/agnostic/gmp/GMPVideoDecoder.cpp
+++ b/dom/media/platforms/agnostic/gmp/GMPVideoDecoder.cpp
@@ -90,18 +90,20 @@ VideoCallbackAdapter::ResetComplete()
   MOZ_ASSERT(IsOnGMPThread());
   mCallback->FlushComplete();
 }
 
 void
 VideoCallbackAdapter::Error(GMPErr aErr)
 {
   MOZ_ASSERT(IsOnGMPThread());
-  mCallback->Error(
-    MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR, RESULT_DETAIL("GMPErr:%x", aErr)));
+  mCallback->Error(MediaResult(aErr == GMPDecodeErr
+                               ? NS_ERROR_DOM_MEDIA_DECODE_ERR
+                               : NS_ERROR_DOM_MEDIA_FATAL_ERR,
+                               RESULT_DETAIL("GMPErr:%x", aErr)));
 }
 
 void
 VideoCallbackAdapter::Terminated()
 {
   // Note that this *may* be called from the proxy thread also.
   mCallback->Error(MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
                                RESULT_DETAIL("Video GMP decoder terminated.")));