diff -r f190f5f694fa -r f71f153dc508 src/pyams_security/zmi/notification.py
--- a/src/pyams_security/zmi/notification.py	Mon Jul 09 13:42:56 2018 +0200
+++ b/src/pyams_security/zmi/notification.py	Thu Jul 12 18:19:23 2018 +0200
@@ -72,11 +72,6 @@
     def getContent(self):
         return query_utility(ISecurityManager)
 
-    def updateWidgets(self, prefix=None):
-        super(SecurityManagerNotificationsEditForm, self).updateWidgets(prefix)
-        if 'signature' in self.widgets:
-            self.widgets['signature'].widget_css_class = 'textarea'
-
 
 @view_config(name='notifications.json', context=ISecurityManager, request_type=IPyAMSLayer,
              permission=MANAGE_SYSTEM_PERMISSION, renderer='json', xhr=True)