--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -6720,28 +6720,32 @@ HTMLMediaElement::SetPlaybackRate(double
 {
   // Changing the playback rate of a media that has more than two channels is
   // not supported.
   if (aPlaybackRate < 0) {
     aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
     return;
   }
 
-  mPlaybackRate = ClampPlaybackRate(aPlaybackRate);
+  if (mPlaybackRate == aPlaybackRate) {
+    return;
+  }
+
+  mPlaybackRate = aPlaybackRate;
 
   if (mPlaybackRate != 0.0 &&
       (mPlaybackRate > THRESHOLD_HIGH_PLAYBACKRATE_AUDIO ||
        mPlaybackRate < THRESHOLD_LOW_PLAYBACKRATE_AUDIO)) {
     SetMutedInternal(mMuted | MUTED_BY_INVALID_PLAYBACK_RATE);
   } else {
     SetMutedInternal(mMuted & ~MUTED_BY_INVALID_PLAYBACK_RATE);
   }
 
   if (mDecoder) {
-    mDecoder->SetPlaybackRate(mPlaybackRate);
+    mDecoder->SetPlaybackRate(ClampPlaybackRate(mPlaybackRate));
   }
   DispatchAsyncEvent(NS_LITERAL_STRING("ratechange"));
 }
 
 NS_IMETHODIMP HTMLMediaElement::SetPlaybackRate(double aPlaybackRate)
 {
   ErrorResult rv;
   SetPlaybackRate(aPlaybackRate, rv);