Index: mono/utils/networking-posix.c
--- mono/utils/networking-posix.c.orig
+++ mono/utils/networking-posix.c
@@ -21,6 +21,7 @@
 #include <sys/socket.h>
 #endif
 #ifdef HAVE_NET_IF_H
+#include <sys/socket.h>
 #include <net/if.h>
 #endif
 #ifdef HAVE_UNISTD_H