diff --git a/message.xml b/message.xml
index 9b4e72cbe8..ce99310cbe 100644
--- a/message.xml
+++ b/message.xml
@@ -2,7 +2,7 @@
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
 <tryton>
-    <data group="1">
+    <data grouped="1">
         <record model="ir.message" id="msg_employee_unique_cost_price_date">
             <field name="text">An employee can only have one cost price by date.</field>
         </record>