diff --git a/yuthon_hr_employee/models/yuthon_hr_department.py b/yuthon_hr_employee/models/yuthon_hr_department.py
index 0662b23b2..e21fab23d 100644
--- a/yuthon_hr_employee/models/yuthon_hr_department.py
+++ b/yuthon_hr_employee/models/yuthon_hr_department.py
@@ -21,4 +21,6 @@ class YuthonHrDepartment(models.Model):
     def _onchange_department_code(self):
         for code in self:
             if code.parent_id.department_code:
-                code.department_code = code.parent_id.department_code + code.department_code
\ No newline at end of file
+                code.department_code = code.parent_id.department_code + code.department_code if code.department_code else ''
+            else:
+                code.department_code = code.department_code
\ No newline at end of file