diff --git a/block.c b/block.c
index 3c04446..9a860f1 100644
--- a/block.c
+++ b/block.c
@@ -1959,6 +1959,9 @@
 {
     BlockDriverState tmp;
 
+    bdrv_drain(bs_new);
+    bdrv_drain(bs_old);
+
     /* The code needs to swap the node_name but simply swapping node_list won't
      * work so first remove the nodes from the graph list, do the swap then
      * insert them back if needed.
@@ -2002,6 +2005,9 @@
         QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list);
     }
 
+    assert(QLIST_EMPTY(&bs_old->tracked_requests));
+    assert(QLIST_EMPTY(&bs_new->tracked_requests));
+
     bdrv_rebind(bs_new);
     bdrv_rebind(bs_old);
 }