diff --git a/doc/conf.py b/doc/conf.py
index af57a6f7b..81ce77095 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -41,16 +41,16 @@ master_doc = 'index'
 
 # General information about the project.
 project = u'Modoboa'
-copyright = u'2012, Antoine Nguyen'
+copyright = u'2013, Antoine Nguyen'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 #
 # The short X.Y version.
-version = '0.9.3'
+version = '0.9'
 # The full version, including alpha/beta/rc tags.
-release = '0.9.3'
+release = '0.9.4'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/doc/getting_started/configuration.rst b/doc/getting_started/configuration.rst
index 60aad1bc3..aefa64534 100644
--- a/doc/getting_started/configuration.rst
+++ b/doc/getting_started/configuration.rst
@@ -114,6 +114,44 @@ modifying the ``TIME_ZONE`` variable. For example::
 
   TIME_ZONE = 'Europe/Paris'
 
+*******************
+Sessions management
+*******************
+
+Modoboa uses `Django's session framework
+<https://docs.djangoproject.com/en/dev/topics/http/sessions/?from=olddocs>`_
+to store per-user information.
+
+Few parameters need to be set in the *settings.py* configuration
+file to make Modoboa behave as expected::
+
+  SESSION_EXPIRE_AT_BROWSER_CLOSE = False # Default value
+  SESSION_COOKIE_AGE = 600 # time in seconds
+
+The first parameter is optional but you must ensure it is set to
+``False`` (the default value).
+
+The second one tells Django that a session inactive for this time
+should be considered as closed. You are free to adjust it according to
+your need.
+
+The default configuration file provided by the *modoboa-admin.py*
+command is properly configured.
+
+Clearing the session table
+==========================
+
+Django does not provide automatic purging. Therefore, it's your job to
+purge expired sessions on a regular basis.
+
+Django provides a sample clean-up script: ``django-admin.py
+cleanup``. That script deletes any session in the session table whose
+``expire_date`` is in the past.
+
+For example, you could setup a cron job to run this script every night::
+
+  0 0 * * * <modoboa_site>/manage.py cleanup
+
 ***********************
 External authentication
 ***********************
@@ -138,7 +176,6 @@ Then, all you have to do is to modify the *settings.py* file:
     AUTHENTICATION_BACKENDS = (
       'django_auth_ldap.backend.LDAPBackend',
       'modoboa.lib.authbackends.SimpleBackend',
-      'django.contrib.auth.backends.ModelBackend',
     )
 
 * Set the required parameters to establish the communication with your
diff --git a/doc/getting_started/upgrade.rst b/doc/getting_started/upgrade.rst
index 74a5b1422..cf9c73f1f 100644
--- a/doc/getting_started/upgrade.rst
+++ b/doc/getting_started/upgrade.rst
@@ -33,6 +33,13 @@ Finally, refer to this page to check if the version you're installing
 requires specific operations. If the version you're looking for is not
 present, it means nothing special is required.
 
+0.9.4: administrative panel performance improved
+================================================
+
+#. Edit the *settings.py* file and remove
+   ``'django.contrib.auth.backends.ModelBackend'`` from the
+   ``AUTHENTICATION_BACKENDS`` variable
+
 0.9.1: standard django application and more
 ===========================================