diff --git a/src/script/squirrel_helper.hpp b/src/script/squirrel_helper.hpp
index 51ce3bf9cb..8870e4c9fc 100644
--- a/src/script/squirrel_helper.hpp
+++ b/src/script/squirrel_helper.hpp
@@ -11,10 +11,9 @@
 #define SQUIRREL_HELPER_HPP
 
 #include "squirrel.hpp"
-#include "../core/alloc_func.hpp"
-#include "../economy_type.h"
 #include "../string_func.h"
 #include "../tile_type.h"
+#include "../core/convertible_through_base.hpp"
 #include "squirrel_helper_type.hpp"
 
 template <class CL, ScriptType ST> const char *GetClassName();
@@ -36,7 +35,6 @@ namespace SQConvert {
 	template <> struct Return<int16_t>        { static inline int Set(HSQUIRRELVM vm, int16_t res)       { sq_pushinteger(vm, res); return 1; } };
 	template <> struct Return<int32_t>        { static inline int Set(HSQUIRRELVM vm, int32_t res)       { sq_pushinteger(vm, res); return 1; } };
 	template <> struct Return<int64_t>        { static inline int Set(HSQUIRRELVM vm, int64_t res)       { sq_pushinteger(vm, res); return 1; } };
-	template <> struct Return<Money>        { static inline int Set(HSQUIRRELVM vm, Money res)       { sq_pushinteger(vm, res); return 1; } };
 	template <> struct Return<TileIndex>    { static inline int Set(HSQUIRRELVM vm, TileIndex res)   { sq_pushinteger(vm, (int32_t)res.base()); return 1; } };
 	template <> struct Return<bool>         { static inline int Set(HSQUIRRELVM vm, bool res)        { sq_pushbool   (vm, res); return 1; } };
 	template <> struct Return<char *>       { /* Do not use char *, use std::optional<std::string> instead. */ };
@@ -52,6 +50,14 @@ namespace SQConvert {
 		}
 	};
 
+	template <ConvertibleThroughBase T> struct Return<T> {
+		static inline int Set(HSQUIRRELVM vm, T res)
+		{
+			sq_pushinteger(vm, res.base());
+			return 1;
+		}
+	};
+
 	template <> struct Return<std::optional<std::string>> {
 		static inline int Set(HSQUIRRELVM vm, std::optional<std::string> res)
 		{
@@ -78,7 +84,6 @@ namespace SQConvert {
 	template <> struct Param<int32_t>        { static inline int32_t       Get(HSQUIRRELVM vm, int index) { SQInteger     tmp; sq_getinteger    (vm, index, &tmp); return tmp; } };
 	template <> struct Param<int64_t>        { static inline int64_t       Get(HSQUIRRELVM vm, int index) { SQInteger     tmp; sq_getinteger    (vm, index, &tmp); return tmp; } };
 	template <> struct Param<TileIndex>    { static inline TileIndex   Get(HSQUIRRELVM vm, int index) { SQInteger     tmp; sq_getinteger    (vm, index, &tmp); return TileIndex((uint32_t)(int32_t)tmp); } };
-	template <> struct Param<Money>        { static inline Money       Get(HSQUIRRELVM vm, int index) { SQInteger     tmp; sq_getinteger    (vm, index, &tmp); return tmp; } };
 	template <> struct Param<bool>         { static inline bool        Get(HSQUIRRELVM vm, int index) { SQBool        tmp; sq_getbool       (vm, index, &tmp); return tmp != 0; } };
 	template <> struct Param<const char *> { /* Do not use const char *, use std::string& instead. */ };
 	template <> struct Param<void *>       { static inline void       *Get(HSQUIRRELVM vm, int index) { SQUserPointer tmp; sq_getuserpointer(vm, index, &tmp); return tmp; } };
@@ -92,6 +97,15 @@ namespace SQConvert {
 		}
 	};
 
+	template <ConvertibleThroughBase T> struct Param<T> {
+		static inline T Get(HSQUIRRELVM vm, int index)
+		{
+			SQInteger tmp;
+			sq_getinteger(vm, index, &tmp);
+			return T{static_cast<T::BaseType>(tmp)};
+		}
+	};
+
 	template <> struct Param<const std::string &> {
 		static inline const std::string Get(HSQUIRRELVM vm, int index)
 		{