diff --git a/tests/test_spidermiddleware_referer.py b/tests/test_spidermiddleware_referer.py
index cefd33e4e..4945ac25d 100644
--- a/tests/test_spidermiddleware_referer.py
+++ b/tests/test_spidermiddleware_referer.py
@@ -891,7 +891,12 @@ class TestSettingsPolicyByName(TestCase):
         # test parsing without space(s) after the comma
         settings1 = Settings(
             {
-                "REFERRER_POLICY": f"some-custom-unknown-policy,{POLICY_SAME_ORIGIN},{POLICY_STRICT_ORIGIN_WHEN_CROSS_ORIGIN},another-custom-unknown-policy"
+                "REFERRER_POLICY": (
+                    f"some-custom-unknown-policy,"
+                    f"{POLICY_SAME_ORIGIN},"
+                    f"{POLICY_STRICT_ORIGIN_WHEN_CROSS_ORIGIN},"
+                    f"another-custom-unknown-policy"
+                )
             }
         )
         mw1 = RefererMiddleware(settings1)
@@ -900,7 +905,11 @@ class TestSettingsPolicyByName(TestCase):
         # test parsing with space(s) after the comma
         settings2 = Settings(
             {
-                "REFERRER_POLICY": f"{POLICY_STRICT_ORIGIN_WHEN_CROSS_ORIGIN},    another-custom-unknown-policy,    {POLICY_UNSAFE_URL}"
+                "REFERRER_POLICY": (
+                    f"{POLICY_STRICT_ORIGIN_WHEN_CROSS_ORIGIN},"
+                    f"    another-custom-unknown-policy,"
+                    f"    {POLICY_UNSAFE_URL}"
+                )
             }
         )
         mw2 = RefererMiddleware(settings2)
@@ -909,7 +918,11 @@ class TestSettingsPolicyByName(TestCase):
     def test_multiple_policy_tokens_all_invalid(self):
         settings = Settings(
             {
-                "REFERRER_POLICY": "some-custom-unknown-policy,another-custom-unknown-policy,yet-another-custom-unknown-policy"
+                "REFERRER_POLICY": (
+                    "some-custom-unknown-policy,"
+                    "another-custom-unknown-policy,"
+                    "yet-another-custom-unknown-policy"
+                )
             }
         )
         with self.assertRaises(RuntimeError):