--- a/src/pyams_i18n/zmi/negotiator.py	Wed Mar 28 15:32:53 2018 +0200
+++ b/src/pyams_i18n/zmi/negotiator.py	Wed Apr 11 11:09:34 2018 +0200
@@ -34,6 +34,8 @@
 class NegotiatorPropertiesEditForm(AdminDialogEditForm):
     """Negotiator properties edit form"""
 
+    prefix = 'negotiator_properties.'
+
     @property
     def title(self):
         return self.context.__name__