diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 209b95f8883995c74d05fb1be3165b91b400c2ef..c36e8a4f805bf3a1a7f780d82c8a976ee4914195 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1751,8 +1751,8 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
 
 static int null_validate_conf(struct nullb_device *dev)
 {
-	dev->blocksize = round_down(dev->blocksize, 512);
-	dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);
+	if (blk_validate_block_size(dev->blocksize))
+		return -EINVAL;
 
 	if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) {
 		if (dev->submit_queues != nr_online_nodes)