Update the type of the tp_free slot.
diff --git a/Doc/ext/typestruct.h b/Doc/ext/typestruct.h
index 85ce049..0afe375 100644
--- a/Doc/ext/typestruct.h
+++ b/Doc/ext/typestruct.h
@@ -65,7 +65,7 @@
     initproc tp_init;
     allocfunc tp_alloc;
     newfunc tp_new;
-    destructor tp_free; /* Low-level free-memory routine */
+    freefunc tp_free; /* Low-level free-memory routine */
     inquiry tp_is_gc; /* For PyObject_IS_GC */
     PyObject *tp_bases;
     PyObject *tp_mro; /* method resolution order */