diff -urN busybox-1.19.4/networking/arping.c busybox-1.19.4.new/networking/arping.c
--- busybox-1.19.4/networking/arping.c	2012-02-04 20:24:55.000000000 +0100
+++ busybox-1.19.4.new/networking/arping.c	2012-11-23 17:22:13.753252564 +0100
@@ -24,6 +24,8 @@
 
 #include <arpa/inet.h>
 #include <net/if.h>
+#include <net/if_arp.h>
+#include <netinet/if_ether.h>
 #include <netinet/ether.h>
 #include <netpacket/packet.h>