--- a/src/pyams_security/zmi/plugin/group.py	Tue Nov 15 10:34:41 2016 +0100
+++ b/src/pyams_security/zmi/plugin/group.py	Tue Nov 15 10:35:49 2016 +0100
@@ -236,7 +236,8 @@
 
     def updateWidgets(self, prefix=None):
         super(LocalGroupAddForm, self).updateWidgets()
-        self.widgets['description'].label_css_class = 'textarea'
+        if 'description' in self.widgets:
+            self.widgets['description'].widget_css_class = 'textarea'
 
     def create(self, data):
         return Group()
@@ -292,7 +293,8 @@
 
     def updateWidgets(self, prefix=None):
         super(LocalGroupEditForm, self).updateWidgets()
-        self.widgets['description'].label_css_class = 'textarea'
+        if 'description' in self.widgets:
+            self.widgets['description'].widget_css_class = 'textarea'
 
 
 @view_config(name='properties.json', context=ILocalGroup, request_type=IPyAMSLayer,