diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index a06fd90..dc27d1f 100644
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -1437,7 +1437,7 @@
 
 /* Add static route into static route configuration. */
 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)
 {
   u_char type = 0;
@@ -1533,7 +1533,7 @@
 
 /* Delete static route from static route configuration. */
 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)
 {
   u_char type = 0;
@@ -2002,7 +2002,8 @@
 /* Add static route into static route configuration. */
 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)
 {
   struct route_node *rn;
   struct static_ipv6 *si;
@@ -2082,7 +2083,7 @@
 /* Delete static route from static route configuration. */
 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)
 {
   struct route_node *rn;
   struct static_ipv6 *si;