diff --git a/block/blk-core.c b/block/blk-core.c
index 9677c6525ed8..936876ab662d 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1401,13 +1401,19 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 	struct blk_plug *plug;
 	struct request *rq;
 	bool ret = false;
+	struct list_head *plug_list;
 
 	plug = current->plug;
 	if (!plug)
 		goto out;
 	*request_count = 0;
 
-	list_for_each_entry_reverse(rq, &plug->list, queuelist) {
+	if (q->mq_ops)
+		plug_list = &plug->mq_list;
+	else
+		plug_list = &plug->list;
+
+	list_for_each_entry_reverse(rq, plug_list, queuelist) {
 		int el_ret;
 
 		if (rq->q == q)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2dc8de86d0d2..88d4e864d4c0 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -950,7 +950,7 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
 
 		if (plug) {
 			blk_mq_bio_to_request(rq, bio);
-			if (list_empty(&plug->list))
+			if (list_empty(&plug->mq_list))
 				trace_block_plug(q);
 			else if (request_count >= BLK_MAX_REQUEST_COUNT) {
 				blk_flush_plug_list(plug, false);