diff --git a/src/ai.c b/src/ai.c
index 885a16c..16b2be9 100644
--- a/src/ai.c
+++ b/src/ai.c
@@ -873,19 +873,25 @@ static int ai_combat(lua_State* L) {
 static int ai_settarget(lua_State* L) {
   LLUA_MIN_ARGS(1);
 
-  if(lua_isnumber(L,1)) pilot_target = (int)lua_tonumber(L,1);
-  return 0;
+  if(lua_isnumber(L,1)) {
+    pilot_target = (int)lua_tonumber(L,1);
+    return 1;
+  }
+
+  LLUA_INVALID_PARAMETER();
 }
 
 /* Set the secondary weapon. Biassed towards launchers.. */
 static int ai_secondary(lua_State* L) {
+  PilotOutfit* po;
+  int i;
+
   if(cur_pilot->secondary) {
     lua_pushstring(L, outfit_getTypeBroad(cur_pilot->secondary->outfit));
     return 1;
   }
 
-  PilotOutfit* po = NULL;
-  int i;
+  po = NULL;
   for(i = 0; i < cur_pilot->noutfits; i++) {
     if((po == NULL) && (outfit_isWeapon(cur_pilot->outfits[i].outfit) ||
                         outfit_isLauncher(cur_pilot->outfits[i].outfit)))