diff --git a/purchase_usability_extension/__init__.py b/purchase_usability_extension/__init__.py
index 872efd9..4fa4d52 100644
--- a/purchase_usability_extension/__init__.py
+++ b/purchase_usability_extension/__init__.py
@@ -1,23 +1,2 @@
 # -*- encoding: utf-8 -*-
-##############################################################################
-#
-#    Purchase Usability Extension module for OpenERP
-#    Copyright (C) 2014 Akretion (http://www.akretion.com)
-#    @author Alexis de Lattre <alexis.delattre@akretion.com>
-#
-#    This program is free software: you can redistribute it and/or modify
-#    it under the terms of the GNU Affero General Public License as
-#    published by the Free Software Foundation, either version 3 of the
-#    License, or (at your option) any later version.
-#
-#    This program is distributed in the hope that it will be useful,
-#    but WITHOUT ANY WARRANTY; without even the implied warranty of
-#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-#    GNU Affero General Public License for more details.
-#
-#    You should have received a copy of the GNU Affero General Public License
-#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-##############################################################################
-
-#from . import purchase_invoice_link
+from . import purchase
diff --git a/purchase_usability_extension/purchase.py b/purchase_usability_extension/purchase.py
new file mode 100644
index 0000000..de965f5
--- /dev/null
+++ b/purchase_usability_extension/purchase.py
@@ -0,0 +1,30 @@
+# -*- encoding: utf-8 -*-
+##############################################################################
+#
+#    Purchase Usability Extension module for Odoo
+#    Copyright (C) 2015 Akretion (http://www.akretion.com)
+#    @author Alexis de Lattre <alexis.delattre@akretion.com>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from openerp import models, fields
+
+
+class PurchaseOrderLine(models.Model):
+    _inherit = 'purchase.order.line'
+    _order = 'order_id, sequence, id'
+
+    sequence = fields.Integer(string='Sequence', default=10)
diff --git a/purchase_usability_extension/purchase_view.xml b/purchase_usability_extension/purchase_view.xml
index 90bd4b4..d1e438b 100644
--- a/purchase_usability_extension/purchase_view.xml
+++ b/purchase_usability_extension/purchase_view.xml
@@ -27,6 +27,9 @@
         <page string="Deliveries &amp; Invoices" position="attributes">
             <attribute name="string">Other Information</attribute>
         </page>
+        <xpath expr="//field[@name='order_line']/tree/field[@name='product_id']" position="before">
+            <field name="sequence" invisible="1"/>
+        </xpath>
     </field>
 </record>