diff --git a/docs/ref/contrib/admin/index.txt b/docs/ref/contrib/admin/index.txt
index 6af2140717..407dd88e71 100644
--- a/docs/ref/contrib/admin/index.txt
+++ b/docs/ref/contrib/admin/index.txt
@@ -41,7 +41,8 @@ If you're not using the default project template, here are the requirements:
    <TEMPLATES-OPTIONS>`.
 
 #. If you've customized the :setting:`MIDDLEWARE` setting,
-   :class:`django.contrib.auth.middleware.AuthenticationMiddleware` and
+   :class:`django.contrib.sessions.middleware.SessionMiddleware`,
+   :class:`django.contrib.auth.middleware.AuthenticationMiddleware`, and
    :class:`django.contrib.messages.middleware.MessageMiddleware` must be
    included.