diff --git a/os_api_ref/http_codes.py b/os_api_ref/http_codes.py
index cc45229..d69847c 100644
--- a/os_api_ref/http_codes.py
+++ b/os_api_ref/http_codes.py
@@ -13,7 +13,7 @@
 from docutils import nodes
 from docutils.parsers.rst.directives.tables import Table
 from docutils.statemachine import ViewList
-from httplib import responses
+from six.moves.http_client import responses
 import yaml
 
 # cache for file -> yaml so we only do the load and check of a yaml
diff --git a/requirements.txt b/requirements.txt
index 4efb7e5..05a0e95 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,5 +4,6 @@
 
 pbr>=1.8 # Apache-2.0
 PyYAML>=3.10.0 # MIT
+six>=1.9.0 # MIT
 sphinx!=1.3b1,<1.4,>=1.2.1 # BSD
 openstackdocstheme>=1.5.0 # Apache-2.0