diff --git a/models/sale_coupon_program.py b/models/sale_coupon_program.py
index 9e2a9cd3c26..7e1ec87cc54 100644
--- a/models/sale_coupon_program.py
+++ b/models/sale_coupon_program.py
@@ -73,6 +73,11 @@ class SaleCouponProgram(models.Model):
         if self.promo_code_usage == 'no_code_needed':
             self.promo_code = False
 
+    @api.onchange('reward_product_id')
+    def _onchange_reward_product_id(self):
+        if self.reward_product_id:
+            self.reward_product_uom_id = self.reward_product_id.uom_id
+
     @api.model
     def create(self, vals):
         program = super(SaleCouponProgram, self).create(vals)
diff --git a/models/sale_order.py b/models/sale_order.py
index 0c608b65b39..d3789d5413b 100644
--- a/models/sale_order.py
+++ b/models/sale_order.py
@@ -37,9 +37,8 @@ class SaleOrder(models.Model):
             order._update_existing_reward_lines()
 
     def copy(self, default=None):
-        order = super(SaleOrder, self).copy(dict(default or {}, order_line=False))
-        for line in self._get_reward_lines():
-            line.copy({'order_id': order.id})
+        order = super(SaleOrder, self).copy(default)
+        order._get_reward_lines().unlink()
         order.with_context(sale_coupon_no_loop=False)._create_new_no_code_promo_reward_lines()
         return order