--- config.h.in.orig	2017-03-14 00:21:41.163356000 +0100
+++ config.h.in	2017-03-14 00:22:05.990654000 +0100
@@ -2289,7 +2289,7 @@
    for clang but remains for g++; see <http://trac.macports.org/ticket/41033>.
    Assume DragonFly and FreeBSD will be similar.  */
 #if (((defined __APPLE__ && defined __MACH__) \
-      || defined __DragonFly__ || defined __FreeBSD__) \
+      || defined __DragonFly__ || defined __BSDSUniX__ || defined __FreeBSD__) \
      && (defined __header_inline \
          ? (defined __cplusplus && defined __GNUC_STDC_INLINE__ \
             && ! defined __clang__) \