diff --git a/docs/source/conf.py b/docs/source/conf.py
index c66221c..684ffb3 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -31,7 +31,7 @@ release = '1.0.0'
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = ["sphinx_rtd_theme", "sphinx.ext.todo", "sphinx.ext.napoleon"]
+extensions = ["sphinx_rtd_theme", "sphinx.ext.todo", "sphinx.ext.napoleon", "sphinx.ext.viewcode"]
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']