diff --git a/docs/conf.py b/docs/conf.py
index cd583937c..85be12f30 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -29,7 +29,8 @@ import shlex
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = []
+extensions = ['sphinx.ext.autodoc', 'sphinx.ext.viewcode',
+              'sphinx.ext.intersphinx']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']