$OpenBSD: patch-configure_ac,v 1.2 2012/09/19 16:35:06 sthen Exp $
--- configure.ac.orig	Tue May  1 20:42:00 2012
+++ configure.ac	Wed Sep 19 14:40:30 2012
@@ -946,7 +946,7 @@ AC_CHECK_MEMBERS([struct ip_mreqn.imr_ifindex], [], []
 AC_MSG_CHECKING([for BSD struct ip_mreq hack])
 AC_TRY_COMPILE([#ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
-#endif],[#if (defined(__FreeBSD__) && ((__FreeBSD_version >= 500022 && __FreeBSD_version < 700000) || (__FreeBSD_version < 500000 && __FreeBSD_version >= 440000))) || (defined(__NetBSD__) && defined(__NetBSD_Version__) && __NetBSD_Version__ >= 106010000)
+#endif],[#if (defined(__FreeBSD__) && ((__FreeBSD_version >= 500022 && __FreeBSD_version < 700000) || (__FreeBSD_version < 500000 && __FreeBSD_version >= 440000))) || (defined(__NetBSD__) && defined(__NetBSD_Version__) && __NetBSD_Version__ >= 106010000) || defined(__OpenBSD__)
   return (0);
 #else
   #error No support for BSD struct ip_mreq hack detected
