diff --git a/bgpd/bgp_table.c b/bgpd/bgp_table.c
index be59832..c212025 100644
--- a/bgpd/bgp_table.c
+++ b/bgpd/bgp_table.c
@@ -230,7 +230,7 @@
 
 /* Find matched prefix. */
 struct bgp_node *
-bgp_node_match (struct bgp_table *table, struct prefix *p)
+bgp_node_match (const struct bgp_table *table, struct prefix *p)
 {
   struct bgp_node *node;
   struct bgp_node *matched;
@@ -256,7 +256,7 @@
 }
 
 struct bgp_node *
-bgp_node_match_ipv4 (struct bgp_table *table, struct in_addr *addr)
+bgp_node_match_ipv4 (const struct bgp_table *table, struct in_addr *addr)
 {
   struct prefix_ipv4 p;
 
@@ -270,7 +270,7 @@
 
 #ifdef HAVE_IPV6
 struct bgp_node *
-bgp_node_match_ipv6 (struct bgp_table *table, struct in6_addr *addr)
+bgp_node_match_ipv6 (const struct bgp_table *table, struct in6_addr *addr)
 {
   struct prefix_ipv6 p;
 
@@ -285,7 +285,7 @@
 
 /* Lookup same prefix node.  Return NULL when we can't find route. */
 struct bgp_node *
-bgp_node_lookup (struct bgp_table *table, struct prefix *p)
+bgp_node_lookup (const struct bgp_table *table, struct prefix *p)
 {
   struct bgp_node *node;
 
@@ -305,7 +305,7 @@
 
 /* Add node to routing table. */
 struct bgp_node *
-bgp_node_get (struct bgp_table *table, struct prefix *p)
+bgp_node_get (struct bgp_table *const table, struct prefix *p)
 {
   struct bgp_node *new;
   struct bgp_node *node;
@@ -405,7 +405,7 @@
 /* Get fist node and lock it.  This function is useful when one want
    to lookup all the node exist in the routing table. */
 struct bgp_node *
-bgp_table_top (struct bgp_table *table)
+bgp_table_top (const struct bgp_table *const table)
 {
   /* If there is no node in the routing table return NULL. */
   if (table->top == NULL)
@@ -499,7 +499,7 @@
 }
 
 unsigned long
-bgp_table_count (struct bgp_table *table)
+bgp_table_count (const struct bgp_table *table)
 {
   return table->count;
 }