diff --git a/src/articulated_vehicles.h b/src/articulated_vehicles.h
--- a/src/articulated_vehicles.h
+++ b/src/articulated_vehicles.h
@@ -18,9 +18,9 @@
 uint CountArticulatedParts(EngineID engine_type, bool purchase_window);
 CargoArray GetCapacityOfArticulatedParts(EngineID engine);
 void AddArticulatedParts(Vehicle *first);
-void GetArticulatedRefitMasks(EngineID engine, bool include_initial_cargo_type, uint32 *union_mask, uint32 *intersection_mask);
-uint32 GetUnionOfArticulatedRefitMasks(EngineID engine, bool include_initial_cargo_type);
-uint32 GetIntersectionOfArticulatedRefitMasks(EngineID engine, bool include_initial_cargo_type);
+void GetArticulatedRefitMasks(EngineID engine, bool include_initial_cargo_type, CargoTypes *union_mask, CargoTypes *intersection_mask);
+CargoTypes GetUnionOfArticulatedRefitMasks(EngineID engine, bool include_initial_cargo_type);
+CargoTypes GetIntersectionOfArticulatedRefitMasks(EngineID engine, bool include_initial_cargo_type);
 bool IsArticulatedVehicleCarryingDifferentCargoes(const Vehicle *v, CargoID *cargo_type);
 bool IsArticulatedVehicleRefittable(EngineID engine);
 bool IsArticulatedEngine(EngineID engine_type);