diff --git a/lib/distribute.c b/lib/distribute.c
index 3d61621..906e3f6 100644
--- a/lib/distribute.c
+++ b/lib/distribute.c
@@ -134,7 +134,7 @@
 /* If two distribute-list have same value then return 1 else return
    0. This function is used by hash package. */
 static int
-distribute_cmp (struct distribute *dist1, struct distribute *dist2)
+distribute_cmp (const struct distribute *dist1, const struct distribute *dist2)
 {
   if (dist1->ifname && dist2->ifname)
     if (strcmp (dist1->ifname, dist2->ifname) == 0)
@@ -769,7 +769,7 @@
 distribute_list_init (int node)
 {
   disthash = hash_create ((unsigned int (*) (void *)) distribute_hash_make,
-                          (int (*) (void *, void *)) distribute_cmp);
+                          (int (*) (const void *, const void *)) distribute_cmp);
 
   if(node==RIP_NODE) {
     install_element (RIP_NODE, &distribute_list_all_cmd);