diff --git a/hr_contract_employee_calendar_planning/hooks.py b/hr_contract_employee_calendar_planning/hooks.py
index cad7803df9f..abcf3abec7d 100644
--- a/hr_contract_employee_calendar_planning/hooks.py
+++ b/hr_contract_employee_calendar_planning/hooks.py
@@ -12,6 +12,8 @@ def post_init_hook(env):
     for employee in employees.filtered("contract_ids"):
         contract_calendar_lines = []
         for contract in employee.contract_ids.sorted("date_start"):
+            if contract.resource_calendar_id == employee.resource_calendar_id:
+                continue
             date_start = contract.date_start
             date_end = contract.date_end
             # filter calendar_ids to check for overlaps with contracts
diff --git a/hr_contract_employee_calendar_planning/tests/test_hr_contract_employee_calendar_planning.py b/hr_contract_employee_calendar_planning/tests/test_hr_contract_employee_calendar_planning.py
index c3befbfbd43..3cbaa544a9b 100644
--- a/hr_contract_employee_calendar_planning/tests/test_hr_contract_employee_calendar_planning.py
+++ b/hr_contract_employee_calendar_planning/tests/test_hr_contract_employee_calendar_planning.py
@@ -72,9 +72,11 @@ def test_calendar_migration_from_contracts_01(self):
         self.env.cr.execute(
             f"UPDATE hr_contract SET resource_calendar_id = {self.calendar1.id} WHERE id = {self.contract_1.id}"  # noqa: E501
         )
+        self.contract_1.invalidate_recordset(["resource_calendar_id"])
         self.env.cr.execute(
             f"UPDATE hr_contract SET resource_calendar_id = {self.calendar2.id} WHERE id = {self.contract_2.id}"  # noqa: E501
         )
+        self.contract_2.invalidate_recordset(["resource_calendar_id"])
         # calendar migration from contracts
         old_calendars = self.employee.calendar_ids
         post_init_hook(self.env)
@@ -103,9 +105,11 @@ def test_calendar_migration_from_contracts_02(self):
         self.env.cr.execute(
             f"UPDATE hr_contract SET resource_calendar_id = {self.calendar1.id} WHERE id = {self.contract_1.id}"  # noqa: E501
         )
+        self.contract_1.invalidate_recordset(["resource_calendar_id"])
         self.env.cr.execute(
             f"UPDATE hr_contract SET resource_calendar_id = {self.calendar2.id} WHERE id = {self.contract_2.id}"  # noqa: E501
         )
+        self.contract_2.invalidate_recordset(["resource_calendar_id"])
         # calendar migration from contracts
         old_calendars = self.employee.calendar_ids
         post_init_hook(self.env)