diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index bdfa707ce236..29c15079c4d5 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2509,6 +2509,14 @@ bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq)
 	if (process_refs == 0 || new_process_refs == 0)
 		return NULL;
 
+	/*
+	 * Make sure merged queues belong to the same parent. Parents could
+	 * have changed since the time we decided the two queues are suitable
+	 * for merging.
+	 */
+	if (new_bfqq->entity.parent != bfqq->entity.parent)
+		return NULL;
+
 	bfq_log_bfqq(bfqq->bfqd, bfqq, "scheduling merge with queue %d",
 		new_bfqq->pid);