diff --git a/block/vmdk.c b/block/vmdk.c
index f5f49018fe..3f8c731e32 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -376,7 +376,7 @@ out:
     return ret;
 }
 
-static int vmdk_is_cid_valid(BlockDriverState *bs)
+static int coroutine_fn vmdk_is_cid_valid(BlockDriverState *bs)
 {
     BDRVVmdkState *s = bs->opaque;
     uint32_t cur_pcid;