diff --git a/addons/sale/sale.py b/addons/sale/sale.py
index 8326fb4a1e5..b3fa9a0ef9a 100644
--- a/addons/sale/sale.py
+++ b/addons/sale/sale.py
@@ -862,6 +862,8 @@ class sale_order_line(osv.osv):
                 flag=False,  # Force name update
                 context=context
             )['value']
+            if defaults.get('tax_id'):
+                defaults['tax_id'] = [[6, 0, defaults['tax_id']]]
             values = dict(defaults, **values)
         return super(sale_order_line, self).create(cr, uid, values, context=context)