diff --git a/letsencrypt/tests/client_test.py b/letsencrypt/tests/client_test.py
index 5e8fd57a7..6a8899c3b 100644
--- a/letsencrypt/tests/client_test.py
+++ b/letsencrypt/tests/client_test.py
@@ -115,7 +115,7 @@ class ClientTest(unittest.TestCase):
         test_csr = le_util.CSR(form="der", file=None, data=CSR_SAN)
         with mock.patch("letsencrypt.client.le_util.CSR") as mock_CSR:
             mock_CSR.return_value = test_csr
-            self.client.config.domains=self.eg_domains
+            self.client.config.domains = self.eg_domains
             self.assertEqual(
                 (mock.sentinel.certr, mock.sentinel.chain),
                 self.client.obtain_certificate_from_csr(mock_process_domain))