diff --git a/block/quorum.c b/block/quorum.c
index a33881a..77e55b2 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -935,8 +935,8 @@
         ret = snprintf(indexstr, 32, "children.%d", i);
         assert(ret < 32);
 
-        ret = bdrv_open_image(&s->bs[i], NULL, options, indexstr, flags,
-                              false, &local_err);
+        ret = bdrv_open_image(&s->bs[i], NULL, options, indexstr, bs,
+                              &child_format, false, &local_err);
         if (ret < 0) {
             goto close_exit;
         }