diff --git a/db/migrate/20210607000000_session_timeout_description.rb b/db/migrate/20210607000000_session_timeout_description.rb
new file mode 100644
index 000000000..e516b9bc4
--- /dev/null
+++ b/db/migrate/20210607000000_session_timeout_description.rb
@@ -0,0 +1,9 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+class SessionTimeoutDescription < ActiveRecord::Migration[5.2]
+  def change
+    return if !Setting.exists?(name: 'system_init_done')
+
+    Setting.find_by(name: 'session_timeout').update(description: 'Defines the session timeout for inactivity of users. Based on the assigned permissions the highest timeout value will be used, otherwise the default.')
+  end
+end
diff --git a/db/seeds/settings.rb b/db/seeds/settings.rb
index 6c987700a..23f137a1d 100644
--- a/db/seeds/settings.rb
+++ b/db/seeds/settings.rb
@@ -1049,7 +1049,7 @@ Setting.create_if_not_exists(
   title:       'Session Timeout',
   name:        'session_timeout',
   area:        'Security::Base',
-  description: 'Defines the session timeout for inactivity of users (in seconds).',
+  description: 'Defines the session timeout for inactivity of users. Based on the assigned permissions the highest timeout value will be used, otherwise the default.',
   options:     {
     form: [
       {