Index: dlls/nsiproxy.sys/ip.c
--- dlls/nsiproxy.sys/ip.c.orig
+++ dlls/nsiproxy.sys/ip.c
@@ -60,6 +60,7 @@
 #endif
 
 #ifdef HAVE_NETINET_IF_ETHER_H
+#include <net/if_arp.h>
 #include <netinet/if_ether.h>
 #endif