diff --git a/addons/sale_margin/sale_margin.py b/addons/sale_margin/sale_margin.py
index 36b0a74015c..5cbb17873c1 100644
--- a/addons/sale_margin/sale_margin.py
+++ b/addons/sale_margin/sale_margin.py
@@ -80,7 +80,7 @@ class sale_order(osv.osv):
 
     _columns = {
         'margin': fields.function(_product_margin, string='Margin', help="It gives profitability by calculating the difference between the Unit Price and the cost price.", store={
-                'sale.order.line': (_get_order, ['margin'], 20),
+                'sale.order.line': (_get_order, ['margin', 'purchase_price'], 20),
                 'sale.order': (lambda self, cr, uid, ids, c={}: ids, ['order_line'], 20),
                 }),
     }