@@ -84,6 +84,11 @@ internal ClassDerivedObject(Type tp) : base(tp)
             oldHandle.Free();
         }
 
+        /// <summary>
+        /// No-op clear. Real cleanup happens in <seealso cref="Finalize(IntPtr)"/>
+        /// </summary>
+        public new static int tp_clear(BorrowedReference ob) => 0;
+
         /// <summary>
         /// Called from Converter.ToPython for types that are python subclasses of managed types.
         /// The referenced python object is returned instead of a new wrapper.
@@ -854,6 +859,21 @@ public static void PyFinalize(IPythonDerivedType obj)
             Finalizer.Instance.AddDerivedFinalizedObject(ref self.RawObj, self.Run);
         }
 
+        internal static void Finalize(IntPtr derived)
+        {
+            bool deleted = CLRObject.reflectedObjects.Remove(derived);
+            Debug.Assert(deleted);
+
+            var @ref = NewReference.DangerousFromPointer(derived);
+
+            ClassBase.tp_clear(@ref.Borrow());
+
+            // rare case when it's needed
+            // matches correspdonging PyObject_GC_UnTrack
+            // in ClassDerivedObject.tp_dealloc
+            Runtime.PyObject_GC_Del(@ref.Steal());
+        }
+
         internal static FieldInfo? GetPyObjField(Type type) => type.GetField(PyObjName, PyObjFlags);
 
         internal static UnsafeReferenceWithRun GetPyObj(IPythonDerivedType obj)
 
@@ -236,18 +236,11 @@ internal nint DisposeAll()
                             continue;
                         }
 
-                        var @ref = NewReference.DangerousFromPointer(derived.PyObj);
-                        GCHandle gcHandle = ManagedType.GetGCHandle(@ref.Borrow());
-
-                        bool deleted = CLRObject.reflectedObjects.Remove(derived.PyObj);
-                        Debug.Assert(deleted);
-                        // rare case when it's needed
-                        // matches correspdonging PyObject_GC_UnTrack
-                        // in ClassDerivedObject.tp_dealloc
-                        Runtime.PyObject_GC_Del(@ref.Steal());
-                        collected++;
+#pragma warning disable CS0618 // Type or member is obsolete. OK for internal use
+                        PythonDerivedType.Finalize(derived.PyObj);
+#pragma warning restore CS0618 // Type or member is obsolete
 
-                        gcHandle.Free();
+                        collected++;
                     }
                 }
                 finally
 
@@ -220,7 +220,8 @@ internal static bool TryFreeGCHandle(BorrowedReference reflectedClrObject, Borro
             IntPtr raw = Util.ReadIntPtr(reflectedClrObject, offset);
             if (raw == IntPtr.Zero) return false;
 
-            ((GCHandle)raw).Free();
+            var handle = (GCHandle)raw;
+            handle.Free();
 
             Util.WriteIntPtr(reflectedClrObject, offset, IntPtr.Zero);
             return true;