diff --git a/src/script/api/script_cargo.cpp b/src/script/api/script_cargo.cpp
--- a/src/script/api/script_cargo.cpp
+++ b/src/script/api/script_cargo.cpp
@@ -70,9 +70,12 @@
 	return (ScriptCargo::TownEffect)::CargoSpec::Get(cargo_type)->town_effect;
 }
 
-/* static */ Money ScriptCargo::GetCargoIncome(CargoID cargo_type, uint32 distance, uint32 days_in_transit)
+/* static */ Money ScriptCargo::GetCargoIncome(CargoID cargo_type, SQInteger distance, SQInteger days_in_transit)
 {
 	if (!IsValidCargo(cargo_type)) return -1;
+
+	distance = Clamp<SQInteger>(distance, 0, UINT32_MAX);
+
 	return ::GetTransportedGoodsIncome(1, distance, Clamp(days_in_transit * 2 / 5, 0, 255), cargo_type);
 }
 
@@ -82,8 +85,11 @@
 	return (ScriptCargo::DistributionType)_settings_game.linkgraph.GetDistributionType(cargo_type);
 }
 
-/* static */ int64 ScriptCargo::GetWeight(CargoID cargo_type, uint32 amount)
+/* static */ SQInteger ScriptCargo::GetWeight(CargoID cargo_type, SQInteger amount)
 {
 	if (!IsValidCargo(cargo_type)) return -1;
+
+	amount = Clamp<SQInteger>(amount, 0, UINT32_MAX);
+
 	return ::CargoSpec::Get(cargo_type)->WeightOfNUnits(amount);
 }