diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 67dcb19..e32b24b 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -225,7 +225,7 @@
 	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;