diff --git a/addons/hr_holidays/i18n/hr_holidays.pot b/addons/hr_holidays/i18n/hr_holidays.pot
index 3c743b36c66..f11266a6272 100644
--- a/addons/hr_holidays/i18n/hr_holidays.pot
+++ b/addons/hr_holidays/i18n/hr_holidays.pot
@@ -4132,6 +4132,12 @@ msgstr ""
 msgid "You cannot delete an allocation request which is in %s state."
 msgstr ""
 
+#. module: hr_holidays
+#: code:addons/hr_holidays/models/hr_leave_allocation.py:0
+#, python-format
+msgid "You cannot delete an allocation request which has some validated leaves."
+msgstr ""
+
 #. module: hr_holidays
 #: code:addons/hr_holidays/models/hr_leave.py:0
 #, python-format
diff --git a/addons/hr_holidays/models/hr_leave_allocation.py b/addons/hr_holidays/models/hr_leave_allocation.py
index 51404fdb5d3..42c639f54b0 100644
--- a/addons/hr_holidays/models/hr_leave_allocation.py
+++ b/addons/hr_holidays/models/hr_leave_allocation.py
@@ -583,6 +583,11 @@ class HolidaysAllocation(models.Model):
         for holiday in self.filtered(lambda holiday: holiday.state not in ['draft', 'cancel', 'confirm']):
             raise UserError(_('You cannot delete an allocation request which is in %s state.') % (state_description_values.get(holiday.state),))
 
+    @api.ondelete(at_uninstall=False)
+    def _unlink_if_no_leaves(self):
+        if any(allocation.holiday_status_id.requires_allocation == 'yes' and allocation.leaves_taken > 0 for allocation in self):
+            raise UserError(_('You cannot delete an allocation request which has some validated leaves.'))
+
     def _get_mail_redirect_suggested_company(self):
         return self.holiday_status_id.company_id