--- a/dom/media/ChannelMediaResource.cpp
+++ b/dom/media/ChannelMediaResource.cpp
@@ -431,18 +431,23 @@ nsresult
 ChannelMediaResource::OnDataAvailable(uint32_t aLoadID,
                                       nsIInputStream* aStream,
                                       uint32_t aCount)
 {
   // This might happen off the main thread.
 
   RefPtr<ChannelMediaResource> self = this;
   nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
-    "ChannelMediaResource::OnDataAvailable",
-    [self, aCount]() { self->mChannelStatistics.AddBytes(aCount); });
+    "ChannelMediaResource::OnDataAvailable", [self, aCount, aLoadID]() {
+      if (aLoadID != self->mLoadID) {
+        // Ignore data from the old channel.
+        return;
+      }
+      self->mChannelStatistics.AddBytes(aCount);
+    });
   mCallback->AbstractMainThread()->Dispatch(r.forget());
 
   Closure closure{ aLoadID, this };
   uint32_t count = aCount;
   while (count > 0) {
     uint32_t read;
     nsresult rv =
       aStream->ReadSegments(CopySegmentToCache, &closure, count, &read);