diff --git a/src/script/api/script_subsidy.cpp b/src/script/api/script_subsidy.cpp
index 7e90f8e9a2..0372f315cb 100644
--- a/src/script/api/script_subsidy.cpp
+++ b/src/script/api/script_subsidy.cpp
@@ -31,7 +31,7 @@
 	return ::Subsidy::Get(subsidy_id)->IsAwarded();
 }
 
-/* static */ bool ScriptSubsidy::Create(CargoID cargo_type, SubsidyParticipantType from_type, uint16 from_id, SubsidyParticipantType to_type, uint16 to_id)
+/* static */ bool ScriptSubsidy::Create(CargoID cargo_type, SubsidyParticipantType from_type, SQInteger from_id, SubsidyParticipantType to_type, SQInteger to_id)
 {
 	EnforcePrecondition(false, ScriptCargo::IsValidCargo(cargo_type));
 	EnforcePrecondition(false, from_type == SPT_INDUSTRY || from_type == SPT_TOWN);
@@ -78,7 +78,7 @@
 	return (SubsidyParticipantType)(uint)::Subsidy::Get(subsidy_id)->src_type;
 }
 
-/* static */ int32 ScriptSubsidy::GetSourceIndex(SubsidyID subsidy_id)
+/* static */ SQInteger ScriptSubsidy::GetSourceIndex(SubsidyID subsidy_id)
 {
 	if (!IsValidSubsidy(subsidy_id)) return INVALID_SOURCE;
 
@@ -92,7 +92,7 @@
 	return (SubsidyParticipantType)(uint)::Subsidy::Get(subsidy_id)->dst_type;
 }
 
-/* static */ int32 ScriptSubsidy::GetDestinationIndex(SubsidyID subsidy_id)
+/* static */ SQInteger ScriptSubsidy::GetDestinationIndex(SubsidyID subsidy_id)
 {
 	if (!IsValidSubsidy(subsidy_id)) return INVALID_SOURCE;
 
diff --git a/src/script/api/script_subsidy.hpp b/src/script/api/script_subsidy.hpp
index a4f9fa6867..b59d8bb591 100644
--- a/src/script/api/script_subsidy.hpp
+++ b/src/script/api/script_subsidy.hpp
@@ -62,7 +62,7 @@ public:
 	 * @pre (to_type   == SPT_INDUSTRY && ScriptIndustry::IsValidIndustry(to_id))   || (to_type   == SPT_TOWN && ScriptTown::IsValidTown(to_id))
 	 * @api -ai
 	 */
-	static bool Create(CargoID cargo_type, SubsidyParticipantType from_type, uint16 from_id, SubsidyParticipantType to_type, uint16 to_id);
+	static bool Create(CargoID cargo_type, SubsidyParticipantType from_type, SQInteger from_id, SubsidyParticipantType to_type, SQInteger to_id);
 
 	/**
 	 * Get the company index of the company this subsidy is awarded to.
@@ -109,7 +109,7 @@ public:
 	 * @pre IsValidSubsidy(subsidy_id).
 	 * @return One of TownID/IndustryID.
 	 */
-	static int32 GetSourceIndex(SubsidyID subsidy_id);
+	static SQInteger GetSourceIndex(SubsidyID subsidy_id);
 
 	/**
 	 * Returns the type of destination of subsidy.
@@ -127,7 +127,7 @@ public:
 	 * @pre IsValidSubsidy(subsidy_id).
 	 * @return One of TownID/IndustryID.
 	 */
-	static int32 GetDestinationIndex(SubsidyID subsidy_id);
+	static SQInteger GetDestinationIndex(SubsidyID subsidy_id);
 };
 
 #endif /* SCRIPT_SUBSIDY_HPP */