diff --git a/dev-requirements.txt b/dev-requirements.txt
index 59b226aa0..584023b8c 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -4,6 +4,7 @@ pytest-cov
 coverage
 mock
 sphinx
+sphinx-rtd-theme
 jinja2
 python-dateutil
 
diff --git a/docs/sphinx/conf.py b/docs/sphinx/conf.py
index 4a8922fe8..e80757c2f 100644
--- a/docs/sphinx/conf.py
+++ b/docs/sphinx/conf.py
@@ -4,7 +4,6 @@
 # See the LICENSE file in the project root for more information
 
 import datetime
-import os
 
 import elasticsearch