diff --git a/include/linux/if.h b/include/linux/if.h
index 186070d..5c9d1fa 100644
--- a/include/linux/if.h
+++ b/include/linux/if.h
@@ -63,6 +63,7 @@
 #define IFF_MASTER_ALB	0x10		/* bonding master, balance-alb.	*/
 #define IFF_BONDING	0x20		/* bonding master or slave	*/
 #define IFF_SLAVE_NEEDARP 0x40		/* need ARPs for validation	*/
+#define IFF_ISATAP	0x80		/* ISATAP interface (RFC4214)	*/
 
 #define IF_GET_IFACE	0x0001		/* for querying only */
 #define IF_GET_PROTO	0x0002