diff --git a/include/linux/fib_rules.h b/include/linux/fib_rules.h
index 51da65b68b85..405e41139a4d 100644
--- a/include/linux/fib_rules.h
+++ b/include/linux/fib_rules.h
@@ -15,6 +15,13 @@
 /* try to find source address in routing lookups */
 #define FIB_RULE_FIND_SADDR	0x00010000
 
+/* fib_rules families. values up to 127 are reserved for real address
+ * families, values above 128 may be used arbitrarily.
+ */
+#define FIB_RULES_IPV4		AF_INET
+#define FIB_RULES_IPV6		AF_INET6
+#define FIB_RULES_DECNET	AF_DECnet
+
 struct fib_rule_hdr {
 	__u8		family;
 	__u8		dst_len;
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index bf919b6acea2..78c85985cb30 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -118,7 +118,11 @@ static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex)
 {
 	struct rtnl_link *tab;
 
-	tab = rtnl_msg_handlers[protocol];
+	if (protocol < NPROTO)
+		tab = rtnl_msg_handlers[protocol];
+	else
+		tab = NULL;
+
 	if (tab == NULL || tab[msgindex].doit == NULL)
 		tab = rtnl_msg_handlers[PF_UNSPEC];
 
@@ -129,7 +133,11 @@ static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
 {
 	struct rtnl_link *tab;
 
-	tab = rtnl_msg_handlers[protocol];
+	if (protocol < NPROTO)
+		tab = rtnl_msg_handlers[protocol];
+	else
+		tab = NULL;
+
 	if (tab == NULL || tab[msgindex].dumpit == NULL)
 		tab = rtnl_msg_handlers[PF_UNSPEC];
 
@@ -1444,9 +1452,6 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		return 0;
 
 	family = ((struct rtgenmsg *)NLMSG_DATA(nlh))->rtgen_family;
-	if (family >= NPROTO)
-		return -EAFNOSUPPORT;
-
 	sz_idx = type>>2;
 	kind = type&3;
 
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index 1c8cc6d5b645..af28dcc21844 100644
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -217,7 +217,7 @@ static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
 }
 
 static struct fib_rules_ops dn_fib_rules_ops_template = {
-	.family		= AF_DECnet,
+	.family		= FIB_RULES_DECNET,
 	.rule_size	= sizeof(struct dn_fib_rule),
 	.addr_size	= sizeof(u16),
 	.action		= dn_fib_rule_action,
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index a18355e15111..3ec84fea5b71 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -246,7 +246,7 @@ static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
 }
 
 static struct fib_rules_ops fib4_rules_ops_template = {
-	.family		= AF_INET,
+	.family		= FIB_RULES_IPV4,
 	.rule_size	= sizeof(struct fib4_rule),
 	.addr_size	= sizeof(u32),
 	.action		= fib4_rule_action,
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 92b2b7fb6c3d..8124f16f2ac2 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -238,7 +238,7 @@ static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
 }
 
 static struct fib_rules_ops fib6_rules_ops_template = {
-	.family			= AF_INET6,
+	.family			= FIB_RULES_IPV6,
 	.rule_size		= sizeof(struct fib6_rule),
 	.addr_size		= sizeof(struct in6_addr),
 	.action			= fib6_rule_action,