Use https:// URLs when referring to python.org hosts.
diff --git a/Doc/conf.py b/Doc/conf.py
index f036f82..8174032 100644
--- a/Doc/conf.py
+++ b/Doc/conf.py
@@ -67,7 +67,7 @@
 }
 
 # Output an OpenSearch description file.
-html_use_opensearch = 'http://docs.python.org/'
+html_use_opensearch = 'https://docs.python.org/'
 
 # Additional static files.
 html_static_path = ['tools/static']