diff --git a/addons/sale_margin/models/sale_order.py b/addons/sale_margin/models/sale_order.py
index 49104b4cfe32fec49eaad4385e1265798cbfb063..73c8fced5d43c6603a40725dc258e1dee3f9d635 100644
--- a/addons/sale_margin/models/sale_order.py
+++ b/addons/sale_margin/models/sale_order.py
@@ -60,7 +60,9 @@ class SaleOrder(models.Model):
     _inherit = "sale.order"
 
     margin = fields.Monetary("Margin", compute='_compute_margin', store=True)
-    margin_percent = fields.Float("Margin (%)", compute='_compute_margin', store=True)
+    margin_percent = fields.Float(
+        "Margin (%)", compute='_compute_margin', store=True, group_operator='avg'
+    )
 
     @api.depends('order_line.margin', 'amount_untaxed')
     def _compute_margin(self):