diff --git a/Upsilon/BaseTypes/UserData/UpsilonBinder.cs b/Upsilon/BaseTypes/UserData/UpsilonBinder.cs
index b5ece23..13cc39b 100644
--- a/Upsilon/BaseTypes/UserData/UpsilonBinder.cs
+++ b/Upsilon/BaseTypes/UserData/UpsilonBinder.cs
@@ -74,6 +74,14 @@ namespace Upsilon.BaseTypes.UserData
                             continue;
                     }
 
+                    if (!typeof(ScriptType).IsAssignableFrom(matchParameter.ParameterType) &&
+                        argument is IUserData ud)
+                    {
+                        var csharpType = ud.GetCSharpType();
+                        if (matchParameter.ParameterType.IsAssignableFrom(csharpType))
+                            continue;
+                    }
+
                     if (!matchParameter.ParameterType.IsAssignableFrom(argumentType))
                     {
                         validMatch = false;