diff --git a/tests/test_forms.py b/tests/test_forms.py
index f8a690a43..f80f93843 100644
--- a/tests/test_forms.py
+++ b/tests/test_forms.py
@@ -8,3 +8,10 @@ def test_auth_token_form(self):
         form = AuthenticationTokenForm(None, None, data={'otp_token': '005428'})
         self.assertTrue(form.is_valid())
         self.assertEqual(form.cleaned_data['otp_token'], '005428')
+
+    def test_auth_token_form_clean_device_id_fail(self):
+        form = AuthenticationTokenForm(None, None, data={'otp_token': '005428',
+                                                         'device_id': '123'})
+        self.assertFalse(form.is_valid())
+        self.assertEqual(form.errors['device_id'],
+                         ['Device id is not valid.'])