diff --git a/backend/acara_donor/factories.py b/backend/acara_donor/factories.py
index e1864b8048b63f83a84c9d3ddc73e5d031181bc7..8a8d85edcb84fac2e1d36ea48b36f13f0b26d446 100644
--- a/backend/acara_donor/factories.py
+++ b/backend/acara_donor/factories.py
@@ -20,7 +20,7 @@ class AcaraDonorFactory(factory.DjangoModelFactory):
     nama_institusi = factory.Faker('company')
     alamat_institusi = factory.Faker('address', locale=LOCALE)
     email_kantor = factory.Faker('company_email', locale=LOCALE)
-    no_telp_kantor = factory.Faker('phone_number')
+    no_telp_kantor = factory.Sequence(lambda n: '+6281-1128-%04d' % n)
 
     nama_koor = factory.Faker('name', locale=LOCALE)
     email_koor = factory.Faker('free_email', locale=LOCALE)