diff --git a/aircraft_cmd.c b/aircraft_cmd.c
--- a/aircraft_cmd.c
+++ b/aircraft_cmd.c
@@ -627,7 +627,7 @@ int32 CmdRefitAircraft(TileIndex tile, u
 	_returned_refit_capacity = pass;
 
 	cost = 0;
-	if (IS_HUMAN_PLAYER(v->owner) && new_cid != v->cargo_type) {
+	if (IsHumanPlayer(v->owner) && new_cid != v->cargo_type) {
 		cost = GetRefitCost(v->engine_type);
 	}