diff --git a/addons/hr_expense/models/hr_expense.py b/addons/hr_expense/models/hr_expense.py
index ce5f93ddbac..e99148d9ead 100644
--- a/addons/hr_expense/models/hr_expense.py
+++ b/addons/hr_expense/models/hr_expense.py
@@ -64,7 +64,7 @@ class HrExpense(models.Model):
     # product_id not required to allow create an expense without product via mail alias, but should be required on the view.
     product_id = fields.Many2one('product.product', string='Category', readonly=True, tracking=True, states={'draft': [('readonly', False)], 'reported': [('readonly', False)], 'refused': [('readonly', False)]}, domain="[('can_be_expensed', '=', True), '|', ('company_id', '=', False), ('company_id', '=', company_id)]", ondelete='restrict')
     product_uom_id = fields.Many2one('uom.uom', string='Unit of Measure', compute='_compute_from_product_id_company_id',
-        store=True, states={'draft': [('readonly', False)], 'refused': [('readonly', False)]},
+        store=True, copy=True, states={'draft': [('readonly', False)], 'refused': [('readonly', False)]},
         default=_default_product_uom_id, domain="[('category_id', '=', product_uom_category_id)]")
     product_uom_category_id = fields.Many2one(related='product_id.uom_id.category_id', readonly=True, string="UoM Category")
     unit_amount = fields.Float("Unit Price", compute='_compute_from_product_id_company_id', store=True, required=True, copy=True,