--- a/dom/html/HTMLTrackElement.cpp
+++ b/dom/html/HTMLTrackElement.cpp
@@ -387,16 +387,20 @@ HTMLTrackElement::ReadyState() const
   }
 
   return mTrack->ReadyState();
 }
 
 void
 HTMLTrackElement::SetReadyState(uint16_t aReadyState)
 {
+  if (ReadyState() == aReadyState) {
+    return;
+  }
+
   if (mTrack) {
     switch (aReadyState) {
       case TextTrackReadyState::Loaded:
         DispatchTrackRunnable(NS_LITERAL_STRING("load"));
         break;
       case TextTrackReadyState::FailedToLoad:
         DispatchTrackRunnable(NS_LITERAL_STRING("error"));
         break;