diff --git a/include/net.h b/include/net.h
index 8a02c92..82500ee 100644
--- a/include/net.h
+++ b/include/net.h
@@ -356,6 +356,7 @@
 #define PROT_VLAN	0x8100		/* IEEE 802.1q protocol		*/
 #define PROT_IPV6	0x86dd		/* IPv6 over bluebook		*/
 #define PROT_PPP_SES	0x8864		/* PPPoE session messages	*/
+#define PROT_NCSI	0x88f8		/* NC-SI control packets        */
 
 #define IPPROTO_ICMP	 1	/* Internet Control Message Protocol	*/
 #define IPPROTO_UDP	17	/* User Datagram Protocol		*/