#endif
#define rx_ifnet_mtu(x) (x)->if_mtu
#define rx_ifnet_flags(x) (x?(x)->if_flags:0)
-#ifdef AFS_OBSD46_ENV
+#if defined(AFS_OBSD46_ENV) || defined(AFS_FBSD81_ENV)
#define rx_ifaddr_withnet(x) ifa_ifwithnet(x, 0)
#else
#define rx_ifaddr_withnet(x) ifa_ifwithnet(x)