diff --git a/Upsilon/BaseTypes/ScriptFunction/ScriptRuntimeFunction.cs b/Upsilon/BaseTypes/ScriptFunction/ScriptRuntimeFunction.cs
index a21e39e..d409cef 100644
--- a/Upsilon/BaseTypes/ScriptFunction/ScriptRuntimeFunction.cs
+++ b/Upsilon/BaseTypes/ScriptFunction/ScriptRuntimeFunction.cs
@@ -56,7 +56,14 @@ namespace Upsilon.BaseTypes.ScriptFunction
                     {
                         var validSymbol =
                             parameterSymbol.BoundTypeDefinition.ValidInternalTypes.Any(validType =>
-                                validType.IsAssignableFrom(parameterType));
+                            {
+                                var b = validType.IsAssignableFrom(parameterType);
+                                if (b) return true;
+                                if (parameterType.IsGenericType &&
+                                    validType.IsAssignableFrom(parameterType.GetGenericTypeDefinition()))
+                                    return true;
+                                return false;
+                            });
                         if (!validSymbol)
                         {
                             isCompatible = false;