diff --git a/purchase_auto_invoice_method/__init__.py b/purchase_auto_invoice_method/__init__.py
index a7f437c..b46d7f4 100644
--- a/purchase_auto_invoice_method/__init__.py
+++ b/purchase_auto_invoice_method/__init__.py
@@ -1,23 +1,3 @@
-# -*- encoding: utf-8 -*-
-##############################################################################
-#
-#    Purchase Auto Invoice Method module for OpenERP
-#    Copyright (C) 2013 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/>.
-#
-##############################################################################
+# -*- coding: utf-8 -*-
 
 from . import purchase
diff --git a/purchase_auto_invoice_method/__openerp__.py b/purchase_auto_invoice_method/__openerp__.py
index 548b970..9c92f9c 100644
--- a/purchase_auto_invoice_method/__openerp__.py
+++ b/purchase_auto_invoice_method/__openerp__.py
@@ -1,8 +1,8 @@
-# -*- encoding: utf-8 -*-
+# -*- coding: utf-8 -*-
 ##############################################################################
 #
-#    Purchase auto invoice method module for OpenERP
-#    Copyright (C) 2013 Akretion (http://www.akretion.com)
+#    Purchase auto invoice method module for Odoo
+#    Copyright (C) 2013-2015 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
@@ -31,13 +31,16 @@
 Purchase Auto Invoice Method
 ============================
 
-Set the Invoice Method of the Purchase Order to 'picking' by default. On Purchase Order validation, if it only contains service lines, the Invoice Method is automatically switched to 'order'.
+This module is usefull for the companies that have set the *Default invoicing control method* to *Based on incoming shipments* in the menu *Settings > Configuration > Purchase*.
 
-Please contact Alexis de Lattre from Akretion <alexis.delattre@akretion.com> for any help or question about this module.
+When you confirm a purchase order, if the *Invoicing Control* is *Based on incoming shipments* and the PO only contains service lines, the *Invoicing Control* is automatically switched to *Based on generated draft invoice*.
+
+This module has been written by Alexis de Lattre from Akretion
+<alexis.delattre@akretion.com>.
     """,
     'author': 'Akretion',
     'website': 'http://www.akretion.com',
-    'depends': ['purchase_partner_invoice_method'],
-    'data': ['partner_data.xml'],
+    'depends': ['purchase'],
+    'data': [],
     'installable': True,
 }
diff --git a/purchase_auto_invoice_method/partner_data.xml b/purchase_auto_invoice_method/partner_data.xml
deleted file mode 100644
index 57796d9..0000000
--- a/purchase_auto_invoice_method/partner_data.xml
+++ /dev/null
@@ -1,23 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<!--
-    Copyright (C) 2015 Akretion (http://www.akretion.com/)
-    @author Alexis de Lattre <alexis.delattre@akretion.com>
-    The licence is in the file __openerp__.py
--->
-
-<openerp>
-<data>
-
-<!-- set supplier invoice method to "picking" by default -->
-<record id="default_supplier_invoice_method" model="ir.property" forcecreate="True">
-    <field name="name">default supplier_invoice_method</field>
-    <field name="fields_id"
-        search="[('model','=','res.partner'), ('name','=','supplier_invoice_method')]"/>
-    <field name="type">selection</field>
-    <field name="value" eval="'picking'"/>
-    <field name="company_id" ref="base.main_company"/>
-</record>
-
-</data>
-</openerp>
diff --git a/purchase_auto_invoice_method/purchase.py b/purchase_auto_invoice_method/purchase.py
index 2e69e84..b054869 100644
--- a/purchase_auto_invoice_method/purchase.py
+++ b/purchase_auto_invoice_method/purchase.py
@@ -1,8 +1,8 @@
-# -*- encoding: utf-8 -*-
+# -*- coding: utf-8 -*-
 ##############################################################################
 #
-#    Purchase Auto Invoice Method module for OpenERP
-#    Copyright (C) 2013 Akretion (http://www.akretion.com)
+#    Purchase Auto Invoice Method module for Odoo
+#    Copyright (C) 2013-2015 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
@@ -20,29 +20,19 @@
 #
 ##############################################################################
 
-from openerp.osv import orm
+from openerp import models, api
 
 
-class purchase_order(orm.Model):
+class PurchaseOrder(models.Model):
     _inherit = 'purchase.order'
 
-    _defaults = {
-        'invoice_method': 'picking',
-    }
-
-    def wkf_confirm_order(self, cr, uid, ids, context=None):
-        invoice_method_order_po_ids = []
-        for po in self.browse(cr, uid, ids, context=context):
-            service_only = True
-            for line in po.order_line:
-                if line.product_id.type != 'service':
-                    service_only = False
-            if service_only:
-                invoice_method_order_po_ids.append(po.id)
-        if invoice_method_order_po_ids:
-            self.write(cr, uid, invoice_method_order_po_ids, {
-                'invoice_method': 'order',
-                }, context=context)
-        res = super(purchase_order, self).wkf_confirm_order(
-            cr, uid, ids, context=context)
-        return res
+    @api.multi
+    def wkf_confirm_order(self):
+        for po in self:
+            if (
+                    po.invoice_method == 'picking' and all([
+                        line.product_id and
+                        line.product_id.type == 'service'
+                        for line in po.order_line])):
+                po.invoice_method = 'order'
+        return super(PurchaseOrder, self).wkf_confirm_order()