--- net-tools-1.60/lib/ec_hw.c
+++ net-tools-1.60/lib/ec_hw.c
@@ -18,6 +18,7 @@
 
 #include <net/if_arp.h>
 #include "net-support.h"
+#include <stddef.h>
 
 struct hwtype ec_hwtype =
 {