diff --git a/docs/conf.py b/docs/conf.py
index f95dbcd..696dcee 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -1,10 +1,8 @@
-# -*- coding: utf-8 -*-
-#
 # Configuration file for the Sphinx documentation builder.
 #
 # This file only contains a selection of the most common options. For a full
 # list see the documentation:
-# http://www.sphinx-doc.org/en/master/config
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
 
 # -- Path setup --------------------------------------------------------------
 
@@ -23,10 +21,10 @@
 copyright = u'Copyright © 2014-2020 Named Data Networking Project.'
 author = u'Named Data Networking Project'
 
-# The short X.Y version
+# The short X.Y version.
 #version = ''
 
-# The full version, including alpha/beta/rc tags
+# The full version, including alpha/beta/rc tags.
 #release = ''
 
 # There are two options for replacing |today|: either, you set today to some
@@ -40,7 +38,7 @@
 
 # If your documentation needs a minimal Sphinx version, state it here.
 #
-needs_sphinx = '1.1'
+needs_sphinx = '1.3'
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
@@ -87,6 +85,9 @@
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
+# Disable syntax highlighting of code blocks by default.
+highlight_language = 'none'
+
 
 # -- Options for LaTeX output ------------------------------------------------