diff --git a/include/netinet/in.h b/include/netinet/in.h
index 8f9377010..278f406ac 100644
--- a/include/netinet/in.h
+++ b/include/netinet/in.h
@@ -29,6 +29,7 @@ typedef uint8_t		sa_family_t;
 /* Protocols */
 #define IPPROTO_IP	0	/* Dummy protocol */
 #define IPPROTO_TCP	6	/* TCP */
+#define IPPROTO_UDP	17	/* UDP */
 
 /* setsockopt options at IP level */
 #define IP_ADD_MEMBERSHIP	12