diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index e0208fa..8d8a5e0 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -62,7 +62,7 @@
 #endif /* PNBBY */
 
 /* Utility mask array. */
-static u_char maskbit[] = {
+static const u_char maskbit[] = {
   0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff
 };
 
diff --git a/ripd/rip_interface.c b/ripd/rip_interface.c
index bdd319e..35685a7 100644
--- a/ripd/rip_interface.c
+++ b/ripd/rip_interface.c
@@ -50,7 +50,7 @@
 static int rip_enable_network_lookup2 (struct connected *connected);
 static void rip_enable_apply_all (void);
 
-struct message ri_version_msg[] = 
+const struct message ri_version_msg[] =
 {
   {RI_RIP_VERSION_1,       "1"},
   {RI_RIP_VERSION_2,       "2"},