pythonnet · lostmsu · Jun 24, 2020 · Jun 23, 2020 · Jun 24, 2020
diff --git a/src/runtime/converter.cs b/src/runtime/converter.cs
@@ -113,6 +113,23 @@ internal static IntPtr ToPython<T>(T value)
            return ToPython(value, typeof(T));
        }

+        private static readonly Func<object, bool> IsTransparentProxy = GetIsTransparentProxy();
+
+        private static bool Never(object _) => false;
+
+        private static Func<object, bool> GetIsTransparentProxy()
+        {
+            var remoting = typeof(int).Assembly.GetType("System.Runtime.Remoting.RemotingServices");
+            if (remoting is null) return Never;
+
+            var isProxy = remoting.GetMethod("IsTransparentProxy", new[] { typeof(object) });
+            if (isProxy is null) return Never;
+
+            return (Func<object, bool>)Delegate.CreateDelegate(
+              typeof(Func<object, bool>), isProxy,
+              throwOnBindFailure: true);
+        }
+
        internal static IntPtr ToPython(object value, Type type)
        {
            if (value is PyObject)
@@ -162,15 +179,8 @@ internal static IntPtr ToPython(object value, Type type)
            var pyderived = value as IPythonDerivedType;
            if (null != pyderived)
            {
-                #if NETSTANDARD
-                return ClassDerivedObject.ToPython(pyderived);
-                #else
-                // if object is remote don't do this
-                if (!System.Runtime.Remoting.RemotingServices.IsTransparentProxy(pyderived))
-                {
+                if (!IsTransparentProxy(pyderived))
                    return ClassDerivedObject.ToPython(pyderived);
-                }
-                #endif
            }

            // hmm - from Python, we almost never care what the declared