diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index ef722f04f88a9..72108404718fe 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -651,6 +651,7 @@ struct compat_cdrom_generic_command {
 	compat_int_t	stat;
 	compat_caddr_t	sense;
 	unsigned char	data_direction;
+	unsigned char	pad[3];
 	compat_int_t	quiet;
 	compat_int_t	timeout;
 	compat_caddr_t	reserved[1];