diff --git a/sys/netinet/tcp.h b/sys/netinet/tcp.h
--- a/sys/netinet/tcp.h
+++ b/sys/netinet/tcp.h
@@ -79,13 +79,13 @@
 	u_short	th_urp;			/* urgent pointer */
 };
 
-static inline uint16_t
+static __inline uint16_t
 tcp_get_flags(const struct tcphdr *th)
 {
         return (((uint16_t)th->th_x2 << 8) | th->th_flags);
 }
 
-static inline void
+static __inline void
 tcp_set_flags(struct tcphdr *th, uint16_t flags)
 {
         th->th_x2    = (flags >> 8) & 0x0f;