diff --git a/doc/source/conf.py b/doc/source/conf.py
index 694f1379..3e4c09cf 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -77,7 +77,7 @@ exclude_patterns = ['_build']
 pygments_style = 'sphinx'
 
 # A list of ignored prefixes for module index sorting.
-#modindex_common_prefix = []
+modindex_common_prefix = ['openstack_auth.']
 
 
 # -- Options for HTML output ---------------------------------------------------