diff --git a/src/vehicle.cpp b/src/vehicle.cpp
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -232,7 +232,7 @@ bool Vehicle::NeedsServicing() const
 			if (IsArticulatedVehicleCarryingDifferentCargoes(v, &cargo_type)) continue;
 
 			/* Did the old vehicle carry anything? */
-			if (cargo_type != CT_INVALID) {
+			if (IsValidCargoID(cargo_type)) {
 				/* We can't refit the vehicle to carry the cargo we want */
 				if (!HasBit(available_cargo_types, cargo_type)) continue;
 			}
@@ -1884,8 +1884,8 @@ LiveryScheme GetEngineLiveryScheme(Engin
 				/* Note: Luckily cargo_type is not needed for engines */
 			}
 
-			if (cargo_type == CT_INVALID) cargo_type = e->GetDefaultCargoType();
-			if (cargo_type == CT_INVALID) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
+			if (!IsValidCargoID(cargo_type)) cargo_type = e->GetDefaultCargoType();
+			if (!IsValidCargoID(cargo_type)) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
 			if (e->u.rail.railveh_type == RAILVEH_WAGON) {
 				if (!CargoSpec::Get(cargo_type)->is_freight) {
 					if (parent_engine_type == INVALID_ENGINE) {
@@ -1924,8 +1924,8 @@ LiveryScheme GetEngineLiveryScheme(Engin
 				e = Engine::Get(engine_type);
 				cargo_type = v->First()->cargo_type;
 			}
-			if (cargo_type == CT_INVALID) cargo_type = e->GetDefaultCargoType();
-			if (cargo_type == CT_INVALID) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
+			if (!IsValidCargoID(cargo_type)) cargo_type = e->GetDefaultCargoType();
+			if (!IsValidCargoID(cargo_type)) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
 
 			/* Important: Use Tram Flag of front part. Luckily engine_type refers to the front part here. */
 			if (HasBit(e->info.misc_flags, EF_ROAD_TRAM)) {
@@ -1937,8 +1937,8 @@ LiveryScheme GetEngineLiveryScheme(Engin
 			}
 
 		case VEH_SHIP:
-			if (cargo_type == CT_INVALID) cargo_type = e->GetDefaultCargoType();
-			if (cargo_type == CT_INVALID) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
+			if (!IsValidCargoID(cargo_type)) cargo_type = e->GetDefaultCargoType();
+			if (!IsValidCargoID(cargo_type)) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
 			return IsCargoInClass(cargo_type, CC_PASSENGERS) ? LS_PASSENGER_SHIP : LS_FREIGHT_SHIP;
 
 		case VEH_AIRCRAFT: