diff --git a/addons/warning/warning.py b/addons/warning/warning.py
index eb8482ee1cb..b68969f8e7b 100644
--- a/addons/warning/warning.py
+++ b/addons/warning/warning.py
@@ -230,7 +230,7 @@ sale_order_line()
 
 class purchase_order_line(osv.osv):
     _inherit = 'purchase.order.line'
-    def product_id_change(self,cr, uid, ids, pricelist, product, qty, uom,
+    def onchange_product_id(self,cr, uid, ids, pricelist, product, qty, uom,
             partner_id, date_order=False, fiscal_position=False, date_planned=False,
             name=False, price_unit=False, notes=False, context=None):
         warning = {}
@@ -258,6 +258,8 @@ class purchase_order_line(osv.osv):
 
         return {'value': result.get('value',{}), 'warning':warning}
 
+    product_id_change = onchange_product_id
+
 purchase_order_line()