silence Sphinx warning
diff --git a/Doc/conf.py b/Doc/conf.py
index 41a6b61..d6bf613 100644
--- a/Doc/conf.py
+++ b/Doc/conf.py
@@ -47,6 +47,7 @@
     'whatsnew/2.3',
     'whatsnew/2.4',
     'whatsnew/2.5',
+    'whatsnew/2.6',
     'maclib/scrap',
     'library/xmllib',
     'library/xml.etree',