diff --git a/addons/purchase_requisition/purchase_requisition.py b/addons/purchase_requisition/purchase_requisition.py
index 43cfe2de069..a458481e524 100644
--- a/addons/purchase_requisition/purchase_requisition.py
+++ b/addons/purchase_requisition/purchase_requisition.py
@@ -259,7 +259,7 @@ class procurement_order(osv.osv):
                     })],
                     'purchase_ids': [(6,0,[po_id])]
                 })
-            self.write(cr,uid,proc_id,{'requisition_id':requisition_id})
+            self.write(cr,uid,[proc_id],{'requisition_id':requisition_id})
         return res
 
 procurement_order()