diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 85599e2..5ab1bce 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -188,7 +188,7 @@ You can sign these electronically (just scroll to the bottom). After that,
 we'll be able to accept your pull requests.
 
 [1]: https://github.com/google/oauth2client
-[2]: https://tox.readthedocs.org/en/latest/
+[2]: https://tox.readthedocs.io/en/latest/
 [3]: https://cloud.google.com/storage/docs/authentication#generating-a-private-key
 [4]: https://developers.google.com/open-source/cla/individual
 [5]: https://developers.google.com/open-source/cla/corporate
@@ -199,6 +199,6 @@ we'll be able to accept your pull requests.
 [10]: #fork-oauth2client
 [11]: #include-tests
 [12]: #make-the-pull-request
-[13]: http://oauth2client.readthedocs.org/en/latest/#using-pypy
+[13]: https://oauth2client.readthedocs.io/en/latest/#using-pypy
 [14]: https://docs.djangoproject.com/en/1.7/faq/install/#what-python-version-can-i-use-with-django
 [15]: https://docs.djangoproject.com/en/1.9/faq/install/#what-python-version-can-i-use-with-django
diff --git a/README.md b/README.md
index c09471d..17e69fc 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 [![Build Status](https://travis-ci.org/google/oauth2client.svg?branch=master)](https://travis-ci.org/google/oauth2client)
 [![Coverage Status](https://coveralls.io/repos/google/oauth2client/badge.svg?branch=master&service=github)](https://coveralls.io/github/google/oauth2client?branch=master)
-[![Documentation Status](https://readthedocs.org/projects/oauth2client/badge/?version=latest)](http://oauth2client.readthedocs.org/)
+[![Documentation Status](https://readthedocs.org/projects/oauth2client/badge/?version=latest)](https://oauth2client.readthedocs.io/)
 
 This is a client library for accessing resources protected by OAuth 2.0.
 
@@ -26,4 +26,4 @@ Supported Python Versions
 We support Python 2.6, 2.7, 3.3+. More information [in the docs][2].
 
 [1]: https://github.com/google/oauth2client/blob/master/CONTRIBUTING.md
-[2]: http://oauth2client.readthedocs.org/#supported-python-versions
+[2]: https://oauth2client.readthedocs.io/#supported-python-versions
diff --git a/docs/conf.py b/docs/conf.py
index 2b16ebc..f84911c 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -11,7 +11,7 @@ import sys
 import mock
 
 # See
-# (http://read-the-docs.readthedocs.org/en/latest/faq.html#\
+# (https://read-the-docs.readthedocs.io/en/latest/faq.html#\
 #  i-get-import-errors-on-libraries-that-depend-on-c-modules)
 
 class Mock(mock.Mock):