diff --git a/zebra/rib.h b/zebra/rib.h
index 1141db1..b21e087 100644
--- a/zebra/rib.h
+++ b/zebra/rib.h
@@ -234,11 +234,11 @@
 void rib_init ();
 
 int
-static_add_ipv4 (struct prefix *p, struct in_addr *gate, char *ifname,
+static_add_ipv4 (struct prefix *p, struct in_addr *gate, const char *ifname,
        u_char flags, u_char distance, u_int32_t vrf_id);
 
 int
-static_delete_ipv4 (struct prefix *p, struct in_addr *gate, char *ifname,
+static_delete_ipv4 (struct prefix *p, struct in_addr *gate, const char *ifname,
 		    u_char distance, u_int32_t vrf_id);
 
 #ifdef HAVE_IPV6
@@ -258,11 +258,12 @@
 
 int
 static_add_ipv6 (struct prefix *p, u_char type, struct in6_addr *gate,
-		 char *ifname, u_char flags, u_char distance, u_int32_t vrf_id);
+		 const char *ifname, u_char flags, u_char distance,
+		 u_int32_t vrf_id);
 
 int
 static_delete_ipv6 (struct prefix *p, u_char type, struct in6_addr *gate,
-		    char *ifname, u_char distance, u_int32_t vrf_id);
+		    const char *ifname, u_char distance, u_int32_t vrf_id);
 
 #endif /* HAVE_IPV6 */