diff --git a/src/kernel/messages.c b/src/kernel/messages.c
index 7b9040745..9875d303e 100644
--- a/src/kernel/messages.c
+++ b/src/kernel/messages.c
@@ -83,7 +83,7 @@ struct message *msg_feedback(const struct unit *u, struct order *ord,
         log_warning("trying to create message of unknown type \"%s\"\n", name);
         if (!mt_find("missing_feedback")) {
             mt_register(mt_new_va("missing_feedback", "unit:unit", 
-                "region:region", "command:order", "name:string", NULL));
+                "region:region", "command:order", "name:string", MT_NEW_END));
         }
         return msg_message("missing_feedback", "name unit region command",
             name, u, u->region, ord);
diff --git a/src/kernel/messages.test.c b/src/kernel/messages.test.c
index 4afe25518..ad6a08071 100644
--- a/src/kernel/messages.test.c
+++ b/src/kernel/messages.test.c
@@ -12,7 +12,7 @@ void test_missing_message(CuTest *tc) {
 
     test_setup();
     message_handle_missing(MESSAGE_MISSING_REPLACE);
-    msg = msg_message("unknown", "unit", NULL);
+    msg = msg_message("unknown", "unit", (unit *)NULL);
     CuAssertPtrNotNull(tc, msg);
     CuAssertPtrNotNull(tc, msg->type);
     CuAssertStrEquals(tc, msg->type->name, "missing_message");
diff --git a/src/spells.c b/src/spells.c
index 8334d19c0..7bab3fd2e 100644
--- a/src/spells.c
+++ b/src/spells.c
@@ -838,7 +838,7 @@ static int sp_magicstreet(castorder * co)
     /* melden, 1x pro Partei */
     {
         message *seen = msg_message("path_effect", "mage region", mage, r);
-        message *unseen = msg_message("path_effect", "mage region", NULL, r);
+        message *unseen = msg_message("path_effect", "mage region", (unit *)NULL, r);
         report_effect(r, mage, seen, unseen);
         msg_release(seen);
         msg_release(unseen);
@@ -895,7 +895,7 @@ static int sp_summonent(castorder * co)
     /* melden, 1x pro Partei */
     {
         message *seen = msg_message("ent_effect", "mage amount", mage, ents);
-        message *unseen = msg_message("ent_effect", "mage amount", NULL, ents);
+        message *unseen = msg_message("ent_effect", "mage amount", (unit *)NULL, ents);
         report_effect(r, mage, seen, unseen);
         msg_release(unseen);
         msg_release(seen);
@@ -989,7 +989,7 @@ static int sp_maelstrom(castorder * co)
     /* melden, 1x pro Partei */
     if (c) {
         message *seen = msg_message("maelstrom_effect", "mage", mage);
-        message *unseen = msg_message("maelstrom_effect", "mage", NULL);
+        message *unseen = msg_message("maelstrom_effect", "mage", (unit *)NULL);
         report_effect(r, mage, seen, unseen);
         msg_release(seen);
         msg_release(unseen);
@@ -1033,7 +1033,7 @@ static int sp_mallorn(castorder * co)
     /* melden, 1x pro Partei */
     {
         message *seen = msg_message("mallorn_effect", "mage", mage);
-        message *unseen = msg_message("mallorn_effect", "mage", NULL);
+        message *unseen = msg_message("mallorn_effect", "mage", (unit *)NULL);
         report_effect(r, mage, seen, unseen);
         msg_release(seen);
         msg_release(unseen);
@@ -1068,7 +1068,7 @@ static int sp_blessedharvest(castorder * co)
         duration, 1.0, 0)) {
         const char * effect = co->sp->sname[0]=='b' ? "harvest_effect" : "raindance_effect";
         message *seen = msg_message(effect, "mage", mage);
-        message *unseen = msg_message(effect, "mage", NULL);
+        message *unseen = msg_message(effect, "mage", (unit *)NULL);
         report_effect(r, mage, seen, unseen);
         msg_release(seen);
         msg_release(unseen);
@@ -1114,7 +1114,7 @@ static int sp_hain(castorder * co)
     {
         message *seen = msg_message("growtree_effect", "mage amount", mage, trees);
         message *unseen =
-            msg_message("growtree_effect", "mage amount", NULL, trees);
+            msg_message("growtree_effect", "mage amount", (unit *)NULL, trees);
         report_effect(r, mage, seen, unseen);
         msg_release(seen);
         msg_release(unseen);
@@ -1160,7 +1160,7 @@ static int sp_mallornhain(castorder * co)
     {
         message *seen = msg_message("growtree_effect", "mage amount", mage, trees);
         message *unseen =
-            msg_message("growtree_effect", "mage amount", NULL, trees);
+            msg_message("growtree_effect", "mage amount", (unit *)NULL, trees);
         report_effect(r, mage, seen, unseen);
         msg_release(seen);
         msg_release(unseen);
@@ -2675,7 +2675,7 @@ static int sp_firewall(castorder * co)
     /* melden, 1x pro Partei */
     {
         message *seen = msg_message("firewall_effect", "mage region", mage, r);
-        message *unseen = msg_message("firewall_effect", "mage region", NULL, r);
+        message *unseen = msg_message("firewall_effect", "mage region", (unit *)NULL, r);
         report_effect(r, mage, seen, unseen);
         msg_release(seen);
         msg_release(unseen);
@@ -4368,7 +4368,7 @@ int sp_puttorest(castorder * co)
     int dead = deathcount(r);
     int laid_to_rest = dice((int)(co->force * 2), 100);
     message *seen = msg_message("puttorest", "mage", mage);
-    message *unseen = msg_message("puttorest", "mage", NULL);
+    message *unseen = msg_message("puttorest", "mage", (unit *)NULL);
 
     if (laid_to_rest < dead) laid_to_rest = dead;
 
diff --git a/src/spy.c b/src/spy.c
index 8d9d4fe8c..94d6c4e7d 100644
--- a/src/spy.c
+++ b/src/spy.c
@@ -466,7 +466,7 @@ static void sink_ship(region * r, ship * sh, unit * saboteur)
                 move_unit(u, safety, NULL);
             }
             else {
-                msg = msg_message("sink_lost_msg", "dead region unit", dead, NULL, u);
+                msg = msg_message("sink_lost_msg", "dead region unit", dead, (region *)NULL, u);
             }
             add_message(&u->faction->msgs, msg);
             msg_release(msg);