diff --git a/Doc/conf.py b/Doc/conf.py
index bca1bef..10b9d6e 100644
--- a/Doc/conf.py
+++ b/Doc/conf.py
@@ -13,7 +13,7 @@
 # General configuration
 # ---------------------
 
-extensions = ['sphinx.addons.refcounting', 'sphinx.addons.coverage']
+extensions = ['sphinx.ext.refcounting', 'sphinx.ext.coverage']
 
 # General substitutions.
 project = 'Python'