diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 67dcb193ab2e228cc1085666de3641320b393daa..e32b24b7a3a270cebdc56e06a0d670452def770c 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -225,7 +225,7 @@ static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
 	struct gendisk *disk = bdev->bd_disk;
 	struct virtio_blk *vblk = disk->private_data;
 
-	if (cmd == 'VBID') {
+	if (cmd == 0x56424944) { /* 'VBID' */
 		void __user *usr_data = (void __user *)data;
 		char id_str[VIRTIO_BLK_ID_BYTES];
 		int err;