PEP 3155 / issue #13448: Qualified name for classes and functions.
diff --git a/Include/object.h b/Include/object.h
index b97f716..3cd5297 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -418,7 +418,7 @@
                                       a given operator (e.g. __getitem__).
                                       see add_operators() in typeobject.c . */
     PyBufferProcs as_buffer;
-    PyObject *ht_name, *ht_slots;
+    PyObject *ht_name, *ht_slots, *ht_qualname;
     /* here are optional user slots, followed by the members. */
 } PyHeapTypeObject;