diff --git a/addons/account/account_invoice.py b/addons/account/account_invoice.py
index 3e86c4963b7..7579191b11f 100644
--- a/addons/account/account_invoice.py
+++ b/addons/account/account_invoice.py
@@ -1060,7 +1060,7 @@ class account_invoice(osv.osv):
                 if obj_inv.type in ('out_invoice', 'out_refund'):
                     ctx = self.get_log_context(cr, uid, context=ctx)
                 message = _("Invoice  '%s' is validated.") % name
-                self.message_post(cr, uid, [inv_id], body=message, context=context)
+                self.message_post(cr, uid, [inv_id], body=message, subtype="account.mt_invoice_validated", context=context)
         return True
 
     def action_cancel(self, cr, uid, ids, *args):
diff --git a/addons/account/data/account_data.xml b/addons/account/data/account_data.xml
index dd27cfbab4e..2dfef225d70 100644
--- a/addons/account/data/account_data.xml
+++ b/addons/account/data/account_data.xml
@@ -563,11 +563,16 @@
 
         <!-- mail: subtypes -->
         <record id="mt_invoice_new" model="mail.message.subtype">
-            <field name="name">created</field>
+            <field name="name">Created</field>
             <field name="res_model">account.invoice</field>
         </record>
+        <record id="mt_invoice_validated" model="mail.message.subtype">
+            <field name="name">Validated</field>
+            <field name="res_model">account.invoice</field>
+            <field name="default" eval="False"/>
+        </record>
         <record id="mt_invoice_paid" model="mail.message.subtype">
-            <field name="name">paid</field>
+            <field name="name">Paid</field>
             <field name="res_model">account.invoice</field>
         </record>
     </data>