diff --git a/conf/defaults.cfg b/conf/defaults.cfg
index 665370f1..023fa811 100644
--- a/conf/defaults.cfg
+++ b/conf/defaults.cfg
@@ -52,6 +52,9 @@ max_attachment_size = 2097152
 # not require a login.
 loginless_ssh_fingerprints = false
 
+# Set cookietimeout in seconds.
+session_age = 1800
+
 [filepaths]
 # The on disk location of media files (does nothing right now).
 media =
diff --git a/ratticweb/settings.py b/ratticweb/settings.py
index 18d32ecb..6260f364 100644
--- a/ratticweb/settings.py
+++ b/ratticweb/settings.py
@@ -233,6 +233,7 @@ def confgetbool(section, var, default):
 # django-user-sessions
 SESSION_ENGINE = 'user_sessions.backends.db'
 SESSION_EXPIRE_AT_BROWSER_CLOSE = True
+SESSION_COOKIE_AGE = int(config.get('ratticweb', 'session_age'))
 
 # Icon configuration
 CRED_ICON_JSON = 'db/icons.json'