--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -3702,17 +3702,16 @@ nsresult HTMLMediaElement::InitializeDec
   if (!originalResource)
     return NS_ERROR_FAILURE;
   RefPtr<MediaDecoder> decoder = aOriginal->Clone(this);
   if (!decoder)
     return NS_ERROR_FAILURE;
 
   LOG(LogLevel::Debug, ("%p Cloned decoder %p from %p", this, decoder.get(), aOriginal));
 
-  decoder->SetMediaSeekable(aOriginal->IsMediaSeekable());
   decoder->SetMediaSeekableOnlyInBufferedRanges(
     aOriginal->IsMediaSeekableOnlyInBufferedRanges());
 
   RefPtr<MediaResource> resource =
     originalResource->CloneData(decoder->GetResourceCallback());
 
   if (!resource) {
     LOG(LogLevel::Debug, ("%p Failed to cloned stream for decoder %p", this, decoder.get()));