diff --git a/docs/conf.py b/docs/conf.py
index ae682af7..3f52e004 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -42,6 +42,7 @@
     'sphinx.ext.autodoc',
     'sphinx.ext.napoleon',
     'sphinx.ext.todo',
+    'sphinx.ext.viewcode',
 ]
 extensions += ['sphinxarg.ext']