--- a/aircraft_cmd.c	Mon Feb 06 08:43:05 2006 +0000
+++ b/aircraft_cmd.c	Mon Feb 06 09:18:04 2006 +0000
@@ -98,7 +98,7 @@
 	if (is_custom_sprite(spritenum)) {
 		int sprite = GetCustomVehicleSprite(v, direction);
 
-		if (sprite) return sprite;
+		if (sprite != 0) return sprite;
 		spritenum = orig_aircraft_vehicle_info[v->engine_type - AIRCRAFT_ENGINES_INDEX].image_index;
 	}
 	return direction + _aircraft_sprite[spritenum];