diff --git a/addons/sale_stock/sale_stock.py b/addons/sale_stock/sale_stock.py
index 11f3e0225fe..1b21f889a78 100644
--- a/addons/sale_stock/sale_stock.py
+++ b/addons/sale_stock/sale_stock.py
@@ -618,13 +618,13 @@ class sale_order_line(osv.osv):
         res_packing = self.product_packaging_change(cr, uid, ids, pricelist, product, qty, uom, partner_id, packaging, context=context)
         res['value'].update(res_packing.get('value', {}))
         warning_msgs = res_packing.get('warning') and res_packing['warning']['message'] or ''
-        compare_qty = float_compare(product_obj.virtual_available * uom2.factor, qty * product_obj.uom_id.factor, precision_rounding=product_obj.uom_id.rounding)
+        compare_qty = float_compare(product_obj.virtual_available, qty, precision_rounding=uom2.rounding)
         if (product_obj.type=='product') and int(compare_qty) == -1 \
-          and (product_obj.procure_method=='make_to_stock'):
+           and (product_obj.procure_method=='make_to_stock'):
             warn_msg = _('You plan to sell %.2f %s but you only have %.2f %s available !\nThe real stock is %.2f %s. (without reservations)') % \
-                    (qty, uom2 and uom2.name or product_obj.uom_id.name,
-                     max(0,product_obj.virtual_available), product_obj.uom_id.name,
-                     max(0,product_obj.qty_available), product_obj.uom_id.name)
+                    (qty, uom2.name,
+                     max(0,product_obj.virtual_available), uom2.name,
+                     max(0,product_obj.qty_available), uom2.name)
             warning_msgs += _("Not enough stock ! : ") + warn_msg + "\n\n"
 
         #update of warning messages