Define IPPROTO_ESP and IPPROTO_AH in case of primitive headers.
diff --git a/iptables.c b/iptables.c
index 73f400b..eb679df 100644
--- a/iptables.c
+++ b/iptables.c
@@ -196,6 +196,14 @@
 	u_int8_t num;
 };
 
+/* Primitive headers... */
+#ifndef IPPROTO_ESP
+#define IPPROTO_ESP 50
+#endif
+#ifndef IPPROTO_AH
+#define IPPROTO_AH 51
+#endif
+
 static const struct pprot chain_protos[] = {
 	{ "tcp", IPPROTO_TCP },
 	{ "udp", IPPROTO_UDP },