--- a/dom/media/AudioConverter.h
+++ b/dom/media/AudioConverter.h
@@ -82,16 +82,26 @@ public:
                   "Conversion not implemented yet");
   }
   explicit AudioDataBuffer(const AlignedFloatBuffer&& aBuffer)
     : mBuffer(Move(aBuffer))
   {
     static_assert(Format == AudioConfig::FORMAT_FLT,
                   "Conversion not implemented yet");
   }
+  AudioDataBuffer& operator=(AudioDataBuffer&& aOther)
+  {
+    mBuffer = Move(aOther.mBuffer);
+    return *this;
+  }
+  AudioDataBuffer& operator=(const AudioDataBuffer& aOther)
+  {
+    mBuffer = aOther.mBuffer;
+    return *this;
+  }
 
   Value* Data() const { return mBuffer.Data(); }
   size_t Length() const { return mBuffer.Length(); }
   size_t Size() const { return mBuffer.Size(); }
   AlignedBuffer<Value> Forget()
   {
     // Correct type -> Just give values as-is.
     return Move(mBuffer);