diff --git a/certbot-dns-route53/certbot_dns_route53/dns_route53_test.py b/certbot-dns-route53/certbot_dns_route53/dns_route53_test.py
index dda354fae..9aec05b6e 100644
--- a/certbot-dns-route53/certbot_dns_route53/dns_route53_test.py
+++ b/certbot-dns-route53/certbot_dns_route53/dns_route53_test.py
@@ -179,7 +179,7 @@ class ClientTest(unittest.TestCase):
     def test_change_txt_record(self):
         self.client._find_zone_id_for_domain = mock.MagicMock()
         self.client._get_validation_rrset = mock.MagicMock(
-            return_value = []
+            return_value=[]
         )
         self.client.r53.change_resource_record_sets = mock.MagicMock(
             return_value={"ChangeInfo": {"Id": 1}})