diff --git a/fedireads/tests/test_signing.py b/fedireads/tests/test_signing.py
index f4da6033c..6cb69f16f 100644
--- a/fedireads/tests/test_signing.py
+++ b/fedireads/tests/test_signing.py
@@ -1,5 +1,11 @@
+from collections import namedtuple
 from urllib.parse import urlsplit
 
+from Crypto import Random
+from Crypto.PublicKey import RSA
+
+import responses
+
 from django.test import TestCase, Client
 from django.utils.http import http_date
 
@@ -8,18 +14,31 @@ from fedireads.broadcast import make_signature
 from fedireads.activitypub import get_follow_request
 from fedireads.settings import DOMAIN
 
+Sender = namedtuple('Sender', ('actor', 'private_key', 'public_key'))
+
 class Signature(TestCase):
     def setUp(self):
         self.mouse = User.objects.create_user('mouse', 'mouse@example.com', '')
         self.rat = User.objects.create_user('rat', 'rat@example.com', '')
         self.cat = User.objects.create_user('cat', 'cat@example.com', '')
 
-    def send_follow(self, signature, now):
+        random_generator = Random.new().read
+        key = RSA.generate(1024, random_generator)
+        private_key = key.export_key().decode('utf8')
+        public_key = key.publickey().export_key().decode('utf8')
+
+        self.fake_remote = Sender(
+            'http://localhost/user/remote',
+            private_key,
+            public_key,
+        )
+
+    def send_follow(self, sender, signature, now):
         c = Client()
         return c.post(
             urlsplit(self.rat.inbox).path,
             data=get_follow_request(
-                self.mouse,
+                sender,
                 self.rat,
             ),
             content_type='application/json',
@@ -34,7 +53,7 @@ class Signature(TestCase):
     def test_correct_signature(self):
         now = http_date()
         signature = make_signature(self.mouse, self.rat.inbox, now)
-        return self.send_follow(signature, now).status_code == 200
+        return self.send_follow(self.mouse, signature, now).status_code == 200
 
     def test_wrong_signature(self):
         ''' Messages must be signed by the right actor.
@@ -42,4 +61,32 @@ class Signature(TestCase):
         '''
         now = http_date()
         signature = make_signature(self.cat, self.rat.inbox, now)
-        assert self.send_follow(signature, now).status_code == 401
+        assert self.send_follow(self.mouse, signature, now).status_code == 401
+
+    @responses.activate
+    def test_remote_signer(self):
+        responses.add(
+            responses.GET,
+            self.fake_remote.actor,
+            json={'publicKey': {
+                'publicKeyPem': self.fake_remote.public_key
+            }},
+            status=200)
+
+        now = http_date()
+        sender = self.fake_remote
+        signature = make_signature(sender, self.rat.inbox, now)
+        assert self.send_follow(sender, signature, now).status_code == 200
+
+    @responses.activate
+    def test_nonexistent_signer(self):
+        responses.add(
+            responses.GET,
+            self.fake_remote.actor,
+            json={'error': 'not found'},
+            status=404)
+
+        now = http_date()
+        sender = self.fake_remote
+        signature = make_signature(sender, self.rat.inbox, now)
+        assert self.send_follow(sender, signature, now).status_code == 401
diff --git a/requirements.txt b/requirements.txt
index 262b6e28a..7c386d2fd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,3 +10,4 @@ pycryptodome==3.9.4
 python-dateutil==2.8.1
 redis==3.4.1
 requests==2.22.0
+responses==0.10.14