diff --git a/include/uapi/linux/netfilter.h b/include/uapi/linux/netfilter.h
index 53411ccc69db..5a79ccb76701 100644
--- a/include/uapi/linux/netfilter.h
+++ b/include/uapi/linux/netfilter.h
@@ -63,7 +63,9 @@ enum {
 	NFPROTO_NETDEV =  5,
 	NFPROTO_BRIDGE =  7,
 	NFPROTO_IPV6   = 10,
+#ifndef __KERNEL__ /* no longer supported by kernel */
 	NFPROTO_DECNET = 12,
+#endif
 	NFPROTO_NUMPROTO,
 };