diff --git a/dlls/mfplat/queue.c b/dlls/mfplat/queue.c
index 1b9ef38a4ee..96dd6dec4dd 100644
--- a/dlls/mfplat/queue.c
+++ b/dlls/mfplat/queue.c
@@ -185,6 +185,8 @@ static HRESULT grab_queue(DWORD queue_id, struct queue **ret)
     MFASYNC_WORKQUEUE_TYPE queue_type;
     struct queue_handle *entry;
 
+    *ret = NULL;
+
     if (!system_queues[SYS_QUEUE_STANDARD].pool)
         return MF_E_SHUTDOWN;