diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index dfdf85080fe..acb8280757f 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -305,13 +305,13 @@ class purchase_order(osv.osv):
     def inv_line_create(self, cr, uid, a, ol):
         return (0, False, {
             'name': ol.name,
-            'account_id': a,
+            'account_id': a.id,
             'price_unit': ol.price_unit or 0.0,
             'quantity': ol.product_qty,
             'product_id': ol.product_id.id or False,
             'uos_id': ol.product_uom.id or False,
             'invoice_line_tax_id': [(6, 0, [x.id for x in ol.taxes_id])],
-            'account_analytic_id': ol.account_analytic_id.id,
+            'account_analytic_id': ol.account_analytic_id.id or False,
         })
 
     def action_cancel_draft(self, cr, uid, ids, *args):