diff --git a/addons/event_sale/models/sale_order.py b/addons/event_sale/models/sale_order.py
index 2ac4deaed5f..4b42f6d8663 100644
--- a/addons/event_sale/models/sale_order.py
+++ b/addons/event_sale/models/sale_order.py
@@ -64,3 +64,8 @@ class SaleOrderLine(models.Model):
     @api.onchange('event_ticket_id')
     def _onchange_event_ticket_id(self):
         self.price_unit = (self.event_id.company_id or self.env.user.company_id).currency_id.compute(self.event_ticket_id.price, self.order_id.currency_id)
+
+    @api.onchange('product_uom', 'product_uom_qty')
+    def product_uom_change(self):
+        if not self.event_ticket_id:
+            super(SaleOrderLine, self).product_uom_change()