diff --git a/PorygonSharp/UserData/UserData.cs b/PorygonSharp/UserData/UserData.cs
index 81b2e85..d6b4f88 100644
--- a/PorygonSharp/UserData/UserData.cs
+++ b/PorygonSharp/UserData/UserData.cs
@@ -121,17 +121,35 @@ namespace PorygonSharp.UserData
 
         private void RegisterFunction(MethodInfo method)
         {
-            var type = ScriptType.ScriptTypeHandler.GetFunctionScriptType(method);
-            if (type == IntPtr.Zero || !type.HasValue)
-                return;
             var fieldName = method.Name.ScriptHash();
-            if (Fields.ContainsKey(fieldName))
-                return;
-            var fieldData = new UserDataField(method);
-            var userDataField = CreateUserDataField(type.Value, fieldData.GetGetterPointer(), IntPtr.Zero);
+            if (Fields.TryGetValue(fieldName, out var f))
+            {
+                if (!(f is UserDataFunctionField func)) 
+                    return;
+                
+                var methodPtr = func.MethodPtr;
+                var ret = ScriptType.ScriptTypeHandler.GetScriptType(method.ReturnType);
+                if (!ret.HasValue) return;
+                var parameters = method.GetParameters()
+                    .Select(x => ScriptType.ScriptTypeHandler.GetScriptType(x.ParameterType))
+                    .ToArray();
+                if (parameters.Any(x => !x.HasValue))
+                    return;
+                RegisterUserDataFunctionScriptTypeOption(methodPtr, ret.Value,
+                    parameters.Select(x => x.Value).ToArray(), parameters.Length);
+                func.RegisterOption(method);
+            }
+            else
+            {
+                var type = ScriptType.ScriptTypeHandler.GetFunctionScriptType(method);
+                if (type == IntPtr.Zero || !type.HasValue)
+                    return;
+                var fieldData = new UserDataFunctionField(method, type.Value);
+                var userDataField = CreateUserDataField(type.Value, fieldData.GetGetterPointer(), IntPtr.Zero);
+                RegisterUserDataField(Id, fieldName, userDataField);
+                Fields.Add(fieldName, fieldData);
+            }
 
-            RegisterUserDataField(Id, fieldName, userDataField);
-            Fields.Add(fieldName, fieldData);
         }
 
         private bool IsCastable(IntPtr scriptTypePtr, bool isExplicit)
@@ -236,6 +254,9 @@ namespace PorygonSharp.UserData
         [DllImport("PorygonLang", EntryPoint = "AddUserdataBinaryOperation", CallingConvention = CallingConvention.Cdecl)]
         private static extern void AddUserdataBinaryOperation(uint id, byte kind, IntPtr operation);
 
+        [DllImport("PorygonLang", EntryPoint = "RegisterUserDataFunctionScriptTypeOption", CallingConvention = CallingConvention.Cdecl)]
+        private static extern IntPtr RegisterUserDataFunctionScriptTypeOption(IntPtr existing, IntPtr returnType, 
+            IntPtr[] parameters, int parameterCount);
 
     }
 }
\ No newline at end of file
diff --git a/PorygonSharp/UserData/UserDataField.cs b/PorygonSharp/UserData/UserDataField.cs
index 80a9b55..c65ba1b 100644
--- a/PorygonSharp/UserData/UserDataField.cs
+++ b/PorygonSharp/UserData/UserDataField.cs
@@ -1,9 +1,7 @@
 using System;
-using System.Linq;
 using System.Reflection;
 using System.Runtime.InteropServices;
 using PorygonSharp.EvalValues;
-using PorygonSharp.Utilities;
 
 namespace PorygonSharp.UserData
 {
@@ -11,11 +9,11 @@ namespace PorygonSharp.UserData
     {
         internal delegate IntPtr GetterDelegate(IntPtr ptr);
         internal delegate void SetterDelegate(IntPtr ptr, IntPtr val);
-        private delegate IntPtr CallerDelegate(IntPtr parent, IntPtr scriptOption,
+        protected delegate IntPtr CallerDelegate(IntPtr parent, IntPtr scriptOption,
             [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 3)]IntPtr[] parameters, int size);
 
-        private readonly GetterDelegate _getter;
-        private readonly SetterDelegate _setter;
+        protected GetterDelegate _getter;
+        protected readonly SetterDelegate _setter;
 
         public UserDataField(FieldInfo field)
         {
@@ -58,30 +56,8 @@ namespace PorygonSharp.UserData
                 };
             }
         }
-
-        public UserDataField(MethodInfo method)
-        {
-            var parameterTypes = method.GetParameters().Select(x => x.ParameterType).ToArray();
-            _getter = ptr =>
-            {
-                var func = new CallerDelegate((parent, scriptOptions, parameters, size) =>
-                {
-
-                    var evaluatedParameters = new object[size];
-                    for (var i = 0; i < size; i++)
-                    {
-                        var eval = new EvalValue(parameters[i]);
-                        evaluatedParameters[i] = Caster.Cast(eval, parameterTypes[i]);
-                    }
-
-                    var parentObj = GCHandle.FromIntPtr(parent).Target;
-                    var result = method.Invoke(parentObj, evaluatedParameters);
-                    return EvalValueCreator.CreateValue(result).GetPointer();
-                });
-                var funcPtr = Marshal.GetFunctionPointerForDelegate(func);
-                return EvalValueCreator.FunctionEvalValue(funcPtr, ptr).GetPointer();
-            };
-        }
+        
+        protected UserDataField(){}
 
         public UserDataField(GetterDelegate getter, SetterDelegate setter)
         {
diff --git a/PorygonSharp/UserData/UserDataFunctionField.cs b/PorygonSharp/UserData/UserDataFunctionField.cs
new file mode 100644
index 0000000..9261294
--- /dev/null
+++ b/PorygonSharp/UserData/UserDataFunctionField.cs
@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using PorygonSharp.EvalValues;
+using PorygonSharp.Utilities;
+
+namespace PorygonSharp.UserData
+{
+    internal class UserDataFunctionField : UserDataField
+    {
+        public readonly IntPtr MethodPtr;
+        private readonly List<CallerDelegate> _callers;
+        public UserDataFunctionField(MethodInfo method, IntPtr methodPtr)
+        {
+            _getter = ptr =>
+            {
+                var funcPtr = Marshal.GetFunctionPointerForDelegate(_callers[0]);
+                var val = EvalValueCreator.FunctionEvalValue(funcPtr, ptr);
+                for (var i = 1; i < _callers.Count; i++)
+                {
+                    funcPtr = Marshal.GetFunctionPointerForDelegate(_callers[i]);
+                    RegisterFunctionEvalValueOption(val.GetPointer(), funcPtr, ptr);
+                }
+                return val.GetPointer();
+            };
+            MethodPtr = methodPtr;
+            _callers = new List<CallerDelegate>(){CreateCaller(method)};
+        }
+
+        private CallerDelegate CreateCaller(MethodInfo method)
+        {
+            var parameterTypes = method.GetParameters().Select(x => x.ParameterType).ToArray();
+            return (parent, scriptOptions, parameters, size) =>
+            {
+                var evaluatedParameters = new object[size];
+                for (var i = 0; i < size; i++)
+                {
+                    var eval = new EvalValue(parameters[i]);
+                    evaluatedParameters[i] = Caster.Cast(eval, parameterTypes[i]);
+                }
+
+                var parentObj = GCHandle.FromIntPtr(parent).Target;
+                var result = method.Invoke(parentObj, evaluatedParameters);
+                return EvalValueCreator.CreateValue(result).GetPointer();
+            };
+        }
+
+        internal void RegisterOption(MethodInfo method)
+        {
+            _callers.Add(CreateCaller(method));
+        }
+        
+        [DllImport("PorygonLang", EntryPoint = "RegisterFunctionEvalValueOption",CallingConvention = CallingConvention.Cdecl)]
+        internal static extern IntPtr RegisterFunctionEvalValueOption(IntPtr val, IntPtr func, IntPtr obj);
+    }
+}
\ No newline at end of file
diff --git a/PorygonSharp/libPorygonLang.so b/PorygonSharp/libPorygonLang.so
index 8df6851..7242a16 100755
Binary files a/PorygonSharp/libPorygonLang.so and b/PorygonSharp/libPorygonLang.so differ