diff --git a/src/script/api/script_cargo.cpp b/src/script/api/script_cargo.cpp
index 49fdc4f294..7354c848c0 100644
--- 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);
 }
diff --git a/src/script/api/script_cargo.hpp b/src/script/api/script_cargo.hpp
index 67a54a3467..c5b5c1b5f0 100644
--- a/src/script/api/script_cargo.hpp
+++ b/src/script/api/script_cargo.hpp
@@ -142,10 +142,12 @@ public:
 	 * @param cargo_type The cargo to transport.
 	 * @pre ScriptCargo::IsValidCargo(cargo_type).
 	 * @param distance The distance the cargo travels from begin to end.
-	 * @param days_in_transit Amount of (game) days the cargo is in transit. The max value of this variable is 637. Any value higher returns the same as 637 would.
+	 *                 The value will be clamped to 0 .. MAX(uint32).
+	 * @param days_in_transit Amount of (game) days the cargo is in transit.
+	 *                        The max value of this variable is 637. Any value higher returns the same as 637 would.
 	 * @return The amount of money that would be earned by this trip.
 	 */
-	static Money GetCargoIncome(CargoID cargo_type, uint32 distance, uint32 days_in_transit);
+	static Money GetCargoIncome(CargoID cargo_type, SQInteger distance, SQInteger days_in_transit);
 
 	/**
 	 * Get the cargo distribution type for a cargo.
@@ -159,10 +161,11 @@ public:
 	 *   cargo for the specified type.
 	 * @param cargo_type The cargo to check on.
 	 * @param amount The quantity of cargo.
+	 *               The value will be clamped to 0 .. MAX(uint32).
 	 * @pre ScriptCargo::IsValidCargo(cargo_type).
 	 * @return The weight in tonnes for that quantity of cargo.
 	 */
-	static int64 GetWeight(CargoID cargo_type, uint32 amount);
+	static SQInteger GetWeight(CargoID cargo_type, SQInteger amount);
 };
 
 #endif /* SCRIPT_CARGO_HPP */