diff --git a/mentions/config.py b/mentions/config.py
index c3cbfb0..9502bdc 100644
--- a/mentions/config.py
+++ b/mentions/config.py
@@ -1,10 +1,13 @@
 """Helper functions that derive from `mentions.options` values."""
+import logging
 from typing import Optional, Set
 from urllib.parse import urljoin
 
 from mentions import options
 from mentions.util import compatibility, get_domain
 
+log = logging.getLogger(__name__)
+
 
 def base_url() -> str:
     """Get the base URL of this server from current `options`."""
@@ -45,6 +48,10 @@ def accept_domain_incoming(
 
     domain = get_domain(url)
 
+    if not domain:
+        log.warning(f"accept_domain_incoming received invalid URL: {url}")
+        return False
+
     if domains_allow:
         return _domain_in_set(domain, domains_allow)
 
@@ -74,6 +81,10 @@ def accept_domain_outgoing(
     """
     domain = get_domain(url)
 
+    if not domain:
+        log.warning(f"accept_domain_outgoing received invalid URL: {url}")
+        return False
+
     if not allow_self_mention and domain == options.domain_name():
         return False
     if domains_allow and domains_deny:
diff --git a/mentions/tasks/incoming/process.py b/mentions/tasks/incoming/process.py
index 6b55397..e8f57d7 100644
--- a/mentions/tasks/incoming/process.py
+++ b/mentions/tasks/incoming/process.py
@@ -38,13 +38,10 @@ def process_incoming_webmention(
 ) -> Optional[Webmention]:
     log.info(f"Processing webmention '{source_url}' -> '{target_url}'")
 
-    domains_allow = domains_allow or options.incoming_domains_allow()
-    domains_deny = domains_deny or options.incoming_domains_deny()
-
     allow_source_domain = config.accept_domain_incoming(
         source_url,
-        domains_allow=domains_allow,
-        domains_deny=domains_deny,
+        domains_allow=domains_allow or options.incoming_domains_allow(),
+        domains_deny=domains_deny or options.incoming_domains_deny(),
     )
     if not allow_source_domain:
         log.warning(
diff --git a/tests/tests/test_tasks/test_incoming_webmention.py b/tests/tests/test_tasks/test_incoming_webmention.py
index 6f2828c..4af08e6 100644
--- a/tests/tests/test_tasks/test_incoming_webmention.py
+++ b/tests/tests/test_tasks/test_incoming_webmention.py
@@ -3,7 +3,9 @@
 """
 import logging
 
-from mentions import config
+from django.test import override_settings
+
+from mentions import options
 from mentions.exceptions import SourceNotAccessible, TargetWrongDomain
 from mentions.models import Webmention
 from mentions.models.mixins import IncomingMentionType
@@ -246,22 +248,7 @@ def test_target_object_with_object_not_required(self):
 
 
 class AllowDenyOptionTests(SimpleTestCase):
-    def test_is_domain_acceptable(self):
-        self.assertTrue(config.accept_domain_incoming("https://allow.org", None, None))
-        self.assertTrue(
-            config.accept_domain_incoming("https://allow.org", {"allow.org"}, None)
-        )
-        self.assertFalse(
-            config.accept_domain_incoming("https://deny.org", {"allow.org"}, None)
-        )
-
-        self.assertTrue(
-            config.accept_domain_incoming("https://allow.org", None, {"deny.org"})
-        )
-        self.assertFalse(
-            config.accept_domain_incoming("https://deny.org", None, {"deny.org"})
-        )
-
+    @override_settings(**{options.SETTING_DOMAINS_INCOMING_ALLOW: {"allow.org"}})
     @patch_http_get(text=SOURCE_TEXT_DEFAULT)
     def test_process_incoming_webmention_with_domains_allow(self):
         self.assertIsNotNone(
@@ -269,7 +256,6 @@ def test_process_incoming_webmention_with_domains_allow(self):
                 testfunc.random_url(subdomain="", domain="allow.org", port=""),
                 TARGET_URL,
                 sent_by=testfunc.random_url(),
-                domains_allow={"allow.org"},
             )
         )
         self.assertIsNone(
@@ -277,10 +263,10 @@ def test_process_incoming_webmention_with_domains_allow(self):
                 testfunc.random_url(subdomain="", domain="other.org", port=""),
                 TARGET_URL,
                 sent_by=testfunc.random_url(),
-                domains_allow={"allow.org"},
             )
         )
 
+    @override_settings(**{options.SETTING_DOMAINS_INCOMING_DENY: {"deny.org"}})
     @patch_http_get(text=SOURCE_TEXT_DEFAULT)
     def test_process_incoming_webmention_with_domains_deny(self):
         self.assertIsNotNone(
@@ -288,7 +274,6 @@ def test_process_incoming_webmention_with_domains_deny(self):
                 testfunc.random_url(subdomain="", domain="allow.org", port=""),
                 TARGET_URL,
                 sent_by=testfunc.random_url(),
-                domains_deny={"deny.org"},
             )
         )
         self.assertIsNone(
@@ -296,14 +281,5 @@ def test_process_incoming_webmention_with_domains_deny(self):
                 testfunc.random_url(subdomain="", domain="deny.org", port=""),
                 TARGET_URL,
                 sent_by=testfunc.random_url(),
-                domains_deny={"deny.org"},
-            )
-        )
-        self.assertIsNone(
-            incoming.process_incoming_webmention(
-                testfunc.random_url(domain="deny.org", port=""),
-                TARGET_URL,
-                sent_by=testfunc.random_url(),
-                domains_deny={"*.deny.org"},
             )
         )