diff --git a/sys/scsi/scsi_message.h b/sys/scsi/scsi_message.h
index bce70db2a198..7163d4951a59 100644
--- a/sys/scsi/scsi_message.h
+++ b/sys/scsi/scsi_message.h
@@ -26,7 +26,7 @@
 
 /* Identify message */		     /* M/M */	
 #define MSG_IDENTIFYFLAG	0x80 
-#define MSG_IDENTIFY(lun, disc)	((disc) ? 0xc0 : MSG_IDENTIFYFLAG) | (lun))
+#define MSG_IDENTIFY(lun, disc)	(((disc) ? 0xc0 : MSG_IDENTIFYFLAG) | (lun))
 #define MSG_ISIDENTIFY(m)	((m) & MSG_IDENTIFYFLAG)
 
 /* Extended messages (opcode and length) */