diff --git a/include/rt_names.h b/include/rt_names.h
index 07a10e0..e5dbd45 100644
--- a/include/rt_names.h
+++ b/include/rt_names.h
@@ -13,6 +13,7 @@
 int rtnl_rttable_a2n(__u32 *id, char *arg);
 int rtnl_rtrealm_a2n(__u32 *id, char *arg);
 int rtnl_dsfield_a2n(__u32 *id, char *arg);
+int rtnl_group_a2n(int *id, char *arg);
 
 const char *inet_proto_n2a(int proto, char *buf, int len);
 int inet_proto_a2n(char *buf);