diff --git a/Upsilon/StandardLibraries/StaticScope.cs b/Upsilon/StandardLibraries/StaticScope.cs
index e74aa90..24d0f19 100644
--- a/Upsilon/StandardLibraries/StaticScope.cs
+++ b/Upsilon/StandardLibraries/StaticScope.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Linq;
@@ -110,7 +111,7 @@ namespace Upsilon.StandardLibraries
             var parameters        = new List<InternalFunctionVariableSymbol.InternalFunctionParameter>();
             for (var i = 0; i < genericParameters.Length - 1; i++)
             {
-                var t = genericParameters[i].GetScriptType();
+                var t = DeriveValidTypes(genericParameters[i]);
                 parameters.Add(new InternalFunctionVariableSymbol.InternalFunctionParameter(t, false));
             }
 
@@ -121,13 +122,9 @@ namespace Upsilon.StandardLibraries
         private static VariableSymbol BuildActionVariableSymbol(string name, System.Type type)
         {
             var genericParameters = type.GetGenericArguments();
-            var parameters        = new List<InternalFunctionVariableSymbol.InternalFunctionParameter>();
-            for (var i = 0; i < genericParameters.Length; i++)
-            {
-                var t = genericParameters[i].GetScriptType();
-                parameters.Add(new InternalFunctionVariableSymbol.InternalFunctionParameter(t, false));
-            }
-            return new InternalFunctionVariableSymbol(name, true, Type.Nil, parameters.ToArray());
+            return new InternalFunctionVariableSymbol(name, true, Type.Nil,
+                genericParameters.Select(DeriveValidTypes).Select(t =>
+                    new InternalFunctionVariableSymbol.InternalFunctionParameter(t, false)).ToArray());
         }
 
         private static Type DeriveValidTypes(System.Type type)
@@ -145,8 +142,15 @@ namespace Upsilon.StandardLibraries
             if (type == typeof(ScriptType))
                 // allows every type
                 return (Type) 255;
+            if (type == typeof(object))
+                // allows every type
+                return (Type) 255;
             if (type.IsEnum)
                 return Type.Number;
+            if (type == typeof(string))
+                return Type.String;
+            if (typeof(IEnumerable).IsAssignableFrom(type))
+                return Type.Table | Type.UserData;
             return Type.UserData;
         }
     }