diff --git a/mozilla/netwerk/base/src/nsStreamListenerProxy.cpp b/mozilla/netwerk/base/src/nsStreamListenerProxy.cpp
index 52c1c6a0cf7..01f3cfe914a 100644
--- a/mozilla/netwerk/base/src/nsStreamListenerProxy.cpp
+++ b/mozilla/netwerk/base/src/nsStreamListenerProxy.cpp
@@ -356,7 +356,8 @@ nsStreamListenerProxy::Init(nsIStreamListener *aListener,
                              PR_TRUE, PR_TRUE);
     if (NS_FAILED(rv)) return rv;
 
-    SetReceiver(aListener);
+    nsCOMPtr<nsIStreamObserver> observer = do_QueryInterface(aListener);
+    SetReceiver(observer);
     return SetEventQueue(aEventQ);
 }
 
diff --git a/mozilla/netwerk/base/src/nsStreamProviderProxy.cpp b/mozilla/netwerk/base/src/nsStreamProviderProxy.cpp
index cc24f5984c5..90d647ad863 100644
--- a/mozilla/netwerk/base/src/nsStreamProviderProxy.cpp
+++ b/mozilla/netwerk/base/src/nsStreamProviderProxy.cpp
@@ -280,6 +280,7 @@ nsStreamProviderProxy::Init(nsIStreamProvider *aProvider,
                              PR_TRUE, PR_TRUE);
     if (NS_FAILED(rv)) return rv;
 
-    SetReceiver(aProvider);
+    nsCOMPtr<nsIStreamObserver> observer = do_QueryInterface(aProvider);
+    SetReceiver(observer);
     return SetEventQueue(aEventQ);
 }