diff --git a/bookwyrm/tests/views/test_inbox.py b/bookwyrm/tests/views/test_inbox.py
index 37cf00ddc..889fdc329 100644
--- a/bookwyrm/tests/views/test_inbox.py
+++ b/bookwyrm/tests/views/test_inbox.py
@@ -6,6 +6,7 @@ from unittest.mock import patch
 
 from django.http import HttpResponseNotAllowed, HttpResponseNotFound
 from django.test import TestCase, Client
+from django.test.client import RequestFactory
 import responses
 
 from bookwyrm import models, views
@@ -18,6 +19,7 @@ class Inbox(TestCase):
     def setUp(self):
         """ basic user and book data """
         self.client = Client()
+        self.factory = RequestFactory()
         self.local_user = models.User.objects.create_user(
             "mouse@example.com",
             "mouse@mouse.com",
@@ -936,3 +938,26 @@ class Inbox(TestCase):
             views.inbox.activity_task(activity)
             self.assertTrue(redis_mock.called)
         self.assertFalse(models.UserBlocks.objects.exists())
+
+    def test_is_blocked_user_agent(self):
+        """ check for blocked servers """
+        request = self.factory.post(
+            "",
+            HTTP_USER_AGENT="http.rb/4.4.1 (Mastodon/3.3.0; +https://mastodon.social/)",
+        )
+        self.assertFalse(views.inbox.is_blocked_user_agent(request))
+
+        models.FederatedServer.objects.create(
+            server_name="mastodon.social", status="blocked"
+        )
+        self.assertTrue(views.inbox.is_blocked_user_agent(request))
+
+    def test_is_blocked_activity(self):
+        """ check for blocked servers """
+        activity = {"actor": "https://mastodon.social/user/whaatever/else"}
+        self.assertFalse(views.inbox.is_blocked_user_agent(activity))
+
+        models.FederatedServer.objects.create(
+            server_name="mastodon.social", status="blocked"
+        )
+        self.assertTrue(views.inbox.is_blocked_user_agent(activity))
diff --git a/bookwyrm/views/inbox.py b/bookwyrm/views/inbox.py
index a4ae1e998..9e5aa0195 100644
--- a/bookwyrm/views/inbox.py
+++ b/bookwyrm/views/inbox.py
@@ -68,6 +68,8 @@ def is_blocked_user_agent(request):
     """ check if a request is from a blocked server based on user agent """
     # check user agent
     user_agent = request.headers.get("User-Agent")
+    if not user_agent:
+        return False
     domain = re.match(regex.domain, user_agent)
     if not domain:
         # idk, we'll try again later with the actor