diff --git a/addons/document/document_view.xml b/addons/document/document_view.xml
index b735d2ce4a4..3376655d29d 100644
--- a/addons/document/document_view.xml
+++ b/addons/document/document_view.xml
@@ -243,7 +243,7 @@
         <field name="type">ir.actions.act_window</field>
         <field name="res_model">ir.attachment</field>
         <field name="view_type">form</field>
-        <field name="view_mode">kanban,form</field>
+        <field name="view_mode">kanban,tree,form</field>
         <field name="help" type="html">
           <p class="oe_view_nocontent_create">
             Click to create a new document. 
diff --git a/addons/mail/mail_message_view.xml b/addons/mail/mail_message_view.xml
index 1c4a7f55c10..6c15114cde6 100644
--- a/addons/mail/mail_message_view.xml
+++ b/addons/mail/mail_message_view.xml
@@ -115,7 +115,7 @@
             </field>
         </record>
         <record id="base.action_attachment" model="ir.actions.act_window">
-            <field name="view_mode">kanban,form</field>
+            <field name="view_mode">kanban,tree,form</field>
         </record>
 
 
diff --git a/addons/project/project.py b/addons/project/project.py
index 883db8fd0be..2249cf07dd5 100644
--- a/addons/project/project.py
+++ b/addons/project/project.py
@@ -214,7 +214,7 @@ class project(osv.osv):
             'res_model': 'ir.attachment',
             'type': 'ir.actions.act_window',
             'view_id': False,
-            'view_mode': 'kanban,form',
+            'view_mode': 'kanban,tree,form',
             'view_type': 'form',
             'limit': 80,
             'context': "{'default_res_model': '%s','default_res_id': %d}" % (self._name, res_id)