Fixes failing fping6 build on OS X 10.8

diff --git a/src/fping.c b/src/fping.c
index b35b5dd3041d47e5e7afb5f4b4ba1b4afc9f8618..c6becd9e2d94f8cc85d00902cc82771fefc40ae7 100644 (file)
--- a/src/fping.c
+++ b/src/fping.c
@@ -54,6 +54,7 @@ extern "C"
 #include <getopt.h>
 #include <stdarg.h>
 
+#define __APPLE_USE_RFC_3542 1
 #include <netinet/in.h>
 
 #include "config.h"