diff --git a/include/linux/rio.h b/include/linux/rio.h
index a90ebadd9da0..abddba9db130 100644
--- a/include/linux/rio.h
+++ b/include/linux/rio.h
@@ -62,7 +62,7 @@
  *
  *	0	RapidIO inbound doorbells
  *	1	RapidIO inbound mailboxes
- *	1	RapidIO outbound mailboxes
+ *	2	RapidIO outbound mailboxes
  */
 #define RIO_DOORBELL_RESOURCE	0
 #define RIO_INB_MBOX_RESOURCE	1