diff --git a/addons/hr_contract/models/hr_contract.py b/addons/hr_contract/models/hr_contract.py
index eda744d43f3..753484d403b 100644
--- a/addons/hr_contract/models/hr_contract.py
+++ b/addons/hr_contract/models/hr_contract.py
@@ -30,7 +30,7 @@ class Contract(models.Model):
         help="End date of the trial period (if there is one).")
     resource_calendar_id = fields.Many2one(
         'resource.calendar', 'Working Schedule', compute='_compute_employee_contract', store=True, readonly=False,
-        default=lambda self: self.env.company.resource_calendar_id.id, copy=False,
+        default=lambda self: self.env.company.resource_calendar_id.id, copy=False, index=True,
         domain="['|', ('company_id', '=', False), ('company_id', '=', company_id)]")
     wage = fields.Monetary('Wage', required=True, tracking=True, help="Employee's monthly gross wage.")
     notes = fields.Text('Notes')