diff --git a/addons/hr/models/hr_employee.py b/addons/hr/models/hr_employee.py
index e9dedf49ec1..5914d335534 100644
--- a/addons/hr/models/hr_employee.py
+++ b/addons/hr/models/hr_employee.py
@@ -33,7 +33,7 @@ class HrEmployeePrivate(models.Model):
     # resource and user
     # required on the resource, make sure required="True" set in the view
     name = fields.Char(string="Employee Name", related='resource_id.name', store=True, readonly=False, tracking=True)
-    user_id = fields.Many2one('res.users', 'User', related='resource_id.user_id', store=True, readonly=False)
+    user_id = fields.Many2one('res.users', 'User', related='resource_id.user_id', store=True, readonly=False, index=True)
     user_partner_id = fields.Many2one(related='user_id.partner_id', related_sudo=False, string="User's partner")
     active = fields.Boolean('Active', related='resource_id.active', default=True, store=True, readonly=False)
     company_id = fields.Many2one('res.company', required=True)
diff --git a/addons/hr_holidays/models/hr_leave.py b/addons/hr_holidays/models/hr_leave.py
index 0908160982d..ad7ca11396d 100644
--- a/addons/hr_holidays/models/hr_leave.py
+++ b/addons/hr_holidays/models/hr_leave.py
@@ -125,7 +125,7 @@ class HolidaysRequest(models.Model):
         "\nThe status is 'Refused', when time off request is refused by manager." +
         "\nThe status is 'Approved', when time off request is approved by manager.")
     report_note = fields.Text('HR Comments', copy=False, groups="hr_holidays.group_hr_holidays_manager")
-    user_id = fields.Many2one('res.users', string='User', related='employee_id.user_id', related_sudo=True, compute_sudo=True, store=True, readonly=True)
+    user_id = fields.Many2one('res.users', string='User', related='employee_id.user_id', related_sudo=True, compute_sudo=True, store=True, readonly=True, index=True)
     manager_id = fields.Many2one('hr.employee', compute='_compute_from_employee_id', store=True, readonly=False)
     # leave type configuration
     holiday_status_id = fields.Many2one(