--- a/dom/media/AudioStream.cpp
+++ b/dom/media/AudioStream.cpp
@@ -473,16 +473,21 @@ AudioStream::Shutdown()
 
   mState = SHUTDOWN;
 }
 
 void
 AudioStream::ResetDefaultDevice()
 {
   MonitorAutoLock mon(mMonitor);
+  if (mState != STARTED && mState != STOPPED) {
+    return;
+  }
+
+  MOZ_ASSERT(mCubebStream);
   auto r = InvokeCubeb(cubeb_stream_reset_default_device);
   if (!(r == CUBEB_OK || r == CUBEB_ERROR_NOT_SUPPORTED)) {
     mState = ERRORED;
   }
 }
 
 int64_t
 AudioStream::GetPosition()