Index: Objects/typeobject.c
===================================================================
--- Objects/typeobject.c	(Revision 88440)
+++ Objects/typeobject.c	(Arbeitskopie)
@@ -2347,6 +2347,17 @@
 	    goto fail;
 	}
 	*(void**)(res_start + slotoffsets[slot->slot]) = slot->pfunc;
+
+        if (slot->slot == Py_tp_doc) {
+            ssize_t len = strlen(slot->pfunc)+1;
+            char *tp_doc = PyObject_MALLOC(len);
+            if (tp_doc == NULL) {
+                Py_DECREF(res);
+                return NULL;
+            }
+            memcpy(tp_doc, slot->pfunc, len);
+            res->ht_type.tp_doc = tp_doc;
+        }
     }
 
     return (PyObject*)res;