diff --git a/ripd/ripd.c b/ripd/ripd.c
index 62d8691..2525679 100644
--- a/ripd/ripd.c
+++ b/ripd/ripd.c
@@ -76,7 +76,7 @@
 };
 
 /* RIP command strings. */
-struct message rip_msg[] = 
+static const struct message rip_msg[] =
 {
   {RIP_REQUEST,    "REQUEST"},
   {RIP_RESPONSE,   "RESPONSE"},
@@ -84,6 +84,7 @@
   {RIP_TRACEOFF,   "TRACEOFF"},
   {RIP_POLL,       "POLL"},
   {RIP_POLL_ENTRY, "POLL ENTRY"},
+  {0, NULL},
 };
 
 /* Utility function to set boradcast option to the socket. */
@@ -3508,7 +3509,7 @@
   struct listnode *node;
   struct interface *ifp;
   struct rip_interface *ri;
-  extern struct message ri_version_msg[];
+  extern const struct message ri_version_msg[];
   const char *send_version;
   const char *receive_version;