diff --git a/Upsilon/Binder/Binder.cs b/Upsilon/Binder/Binder.cs
index c08a717..898aa7d 100644
--- a/Upsilon/Binder/Binder.cs
+++ b/Upsilon/Binder/Binder.cs
@@ -281,9 +281,12 @@ namespace Upsilon.Binder
             }
             else if (resolved is UserDataVariableSymbol udSymbol)
             {
-                if (udSymbol.Parent != null  && udSymbol.Parent.Properties[resolved.Name] is UserDataBoundMethod ubMethod)
+                if (udSymbol.Parent != null )
                 {
-                    returnType = ubMethod.ResultType;
+                    if (udSymbol.Parent.Properties.TryGetValue(resolved.Name, out var ubProperty) && ubProperty is UserDataBoundMethod ubMethod)
+                    {
+                        returnType = ubMethod.ResultType;
+                    }
                 }
             }
             return new BoundFunctionCallExpression(expression, parameters.ToImmutable(), e.Span, returnType);