diff --git a/Objects/object.c b/Objects/object.c
index 27f89e8d752..6bb10eb1326 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1996,8 +1996,21 @@ _PyTypes_FiniTypes(PyInterpreterState *interp)
         PyTypeObject *type = static_types[i];
         // Cannot delete a type if it still has subclasses
         if (type->tp_subclasses != NULL) {
+            fprintf(stderr, "Cannot clear type '%s': it still has subclasses\n", type->tp_name);
+            //_PyObject_Dump(type->tp_subclasses);
+            {
+                Py_ssize_t i = 0;
+                PyObject *ref;
+                while (PyDict_Next(type->tp_subclasses, &i, NULL, &ref)) {
+                    PyObject *obj = PyWeakref_GET_OBJECT(ref);
+                    PyTypeObject *subclass = _PyType_CAST(obj);
+                    fprintf(stderr, "* %s\n", subclass->tp_name);
+                }
+
+            }
             continue;
         }
+        //fprintf(stderr, "Deallocate type '%s'\n", type->tp_name);
         _PyStaticType_Dealloc(type);
     }
 }