diff --git a/docs/examples/real_world_example.rst b/docs/examples/real_world_example.rst
index e85a94ab..86a542e3 100644
--- a/docs/examples/real_world_example.rst
+++ b/docs/examples/real_world_example.rst
@@ -8,6 +8,11 @@ a web application might look like using the `Flask web framework
 <http://flask.pocoo.org/>`_ and GitHub as a provider. It should be easily
 transferrable to any web framework.
 
+.. note:: While the flow remains the same across moat providers, Github is special in that
+          the ``redirect_uri`` parameter is optional. This means that it may be necessary to
+          explicitly pass a redirect_uri to the ``OAuth2Session`` object (e.g. when creating
+          a custom OAuthProvider with ``flask-oauthlib``).
+
 .. code-block:: python
 
     from requests_oauthlib import OAuth2Session