diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 38e7bf3c3b4f..56e6fb51316d 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -3348,6 +3348,7 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
 		wbt_enable_default(disk);
 
 	blk_mq_unquiesce_queue(disk->queue);
+	mutex_unlock(&disk->queue->elevator_lock);
 	blk_mq_unfreeze_queue(disk->queue, memflags);
 
 	blkg_conf_exit(&ctx);