diff --git a/src/vehicle.h b/src/vehicle.h
--- a/src/vehicle.h
+++ b/src/vehicle.h
@@ -333,7 +333,7 @@ int CheckTrainStoppedInDepot(const Vehic
 
 bool VehicleNeedsService(const Vehicle *v);
 
-uint GenerateVehicleSortList(const Vehicle*** sort_list, uint16 *length_of_array, byte type, PlayerID owner, uint16 index, uint16 window_type);
+uint GenerateVehicleSortList(const Vehicle*** sort_list, uint16 *length_of_array, byte type, PlayerID owner, uint32 index, uint16 window_type);
 void BuildDepotVehicleList(byte type, TileIndex tile, Vehicle ***engine_list, uint16 *engine_list_length, uint16 *engine_count, Vehicle ***wagon_list, uint16 *wagon_list_length, uint16 *wagon_count);
 int32 SendAllVehiclesToDepot(byte type, uint32 flags, bool service, PlayerID owner, uint16 vlw_flag, uint32 id);
 bool IsVehicleInDepot(const Vehicle *v);