diff --git a/tests/app/main/test_validators.py b/tests/app/main/test_validators.py
index 91a7c5fa5..88673ee04 100644
--- a/tests/app/main/test_validators.py
+++ b/tests/app/main/test_validators.py
@@ -210,3 +210,7 @@ def test_sms_sender_form_validation(
     form.sms_sender.data = '0'
     form.validate()
     assert 'Enter 3 characters or more' == form.errors['sms_sender'][0]
+
+    form.sms_sender.data = '000'
+    form.validate()
+    assert not form.errors