diff --git a/modoboa/core/templates/settings.py b/modoboa/core/templates/settings.py
index 54a900da9..46c5fcf3f 100644
--- a/modoboa/core/templates/settings.py
+++ b/modoboa/core/templates/settings.py
@@ -112,6 +112,7 @@ MIDDLEWARE_CLASSES = (
     'django.middleware.locale.LocaleMiddleware',
     # Uncomment the next line for simple clickjacking protection:
     # 'django.middleware.clickjacking.XFrameOptionsMiddleware',
+    'reversion.middleware.RevisionMiddleware',
 
     'modoboa.lib.middleware.AjaxLoginRedirect',
     'modoboa.lib.middleware.CommonExceptionCatcher',