diff --git a/doc/conf.py b/doc/conf.py
index 2352d1f46..2444e2fc0 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -38,6 +38,7 @@ extensions = [
     'sphinx.ext.githubpages',
     'sphinx.ext.graphviz',
     'sphinx.ext.autodoc',
+    'recommonmark',
 ]
 
 source_parsers = {