diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index 3862d9c08f..210dd1ccaf 100644
--- a/synapse/appservice/__init__.py
+++ b/synapse/appservice/__init__.py
@@ -52,11 +52,12 @@ class ApplicationService:
         self,
         token,
         hostname,
+        *,
+        id,
+        sender,
         url=None,
         namespaces=None,
         hs_token=None,
-        sender=None,
-        id=None,
         protocols=None,
         rate_limited=True,
         ip_range_whitelist=None,
diff --git a/tests/api/test_ratelimiting.py b/tests/api/test_ratelimiting.py
index 1e1f30d790..fe504d0869 100644
--- a/tests/api/test_ratelimiting.py
+++ b/tests/api/test_ratelimiting.py
@@ -43,7 +43,7 @@ class TestRatelimiter(unittest.TestCase):
 
     def test_allowed_appservice_ratelimited_via_can_requester_do_action(self):
         appservice = ApplicationService(
-            None, "example.com", id="foo", rate_limited=True,
+            None, "example.com", id="foo", rate_limited=True, sender="@as:example.com",
         )
         as_requester = create_requester("@user:example.com", app_service=appservice)
 
@@ -68,7 +68,7 @@ class TestRatelimiter(unittest.TestCase):
 
     def test_allowed_appservice_via_can_requester_do_action(self):
         appservice = ApplicationService(
-            None, "example.com", id="foo", rate_limited=False,
+            None, "example.com", id="foo", rate_limited=False, sender="@as:example.com",
         )
         as_requester = create_requester("@user:example.com", app_service=appservice)
 
diff --git a/tests/appservice/test_appservice.py b/tests/appservice/test_appservice.py
index 236b608d58..0bffeb1150 100644
--- a/tests/appservice/test_appservice.py
+++ b/tests/appservice/test_appservice.py
@@ -31,6 +31,7 @@ class ApplicationServiceTestCase(unittest.TestCase):
     def setUp(self):
         self.service = ApplicationService(
             id="unique_identifier",
+            sender="@as:test",
             url="some_url",
             token="some_token",
             hostname="matrix.org",  # only used by get_groups_for_user
diff --git a/tests/rest/client/v2_alpha/test_register.py b/tests/rest/client/v2_alpha/test_register.py
index 2fc3a60fc5..98c3887bbf 100644
--- a/tests/rest/client/v2_alpha/test_register.py
+++ b/tests/rest/client/v2_alpha/test_register.py
@@ -55,6 +55,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             self.hs.config.server_name,
             id="1234",
             namespaces={"users": [{"regex": r"@as_user.*", "exclusive": True}]},
+            sender="@as:test",
         )
 
         self.hs.get_datastore().services_cache.append(appservice)