diff --git a/docs/source/conf.py b/docs/source/conf.py
index 5b36714..10a7cea 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -30,7 +30,7 @@ from recommonmark.parser import CommonMarkParser
 # ones.
 extensions = [
     'sphinx.ext.autodoc',
-    'sphinx_autodoc_typehints'
+    'sphinx_autodoc_typehints',
     'sphinx.ext.doctest',
     'sphinx.ext.intersphinx',
     'sphinx.ext.todo',