diff --git a/changelog.d/14887.misc b/changelog.d/14887.misc
new file mode 100644
index 0000000000000000000000000000000000000000..9f5384e60e78ecd168c028536d5e61a3f6bb840e
--- /dev/null
+++ b/changelog.d/14887.misc
@@ -0,0 +1 @@
+Add missing type hints.
\ No newline at end of file
diff --git a/mypy.ini b/mypy.ini
index 63366dad99ccfb33e27ccc3729df8d436efce479..248402532e87c14eb9455def5138a3ad92fdf756 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -39,7 +39,6 @@ exclude = (?x)
    |tests/events/test_utils.py
    |tests/federation/test_federation_catch_up.py
    |tests/federation/test_federation_sender.py
-   |tests/federation/transport/test_knocking.py
    |tests/handlers/test_typing.py
    |tests/http/federation/test_matrix_federation_agent.py
    |tests/http/federation/test_srv_resolver.py
diff --git a/tests/federation/transport/test_knocking.py b/tests/federation/transport/test_knocking.py
index d21c11b716cd1f9c9c5f4e740e13ab04e8bcf3a1..ff589c0b6ca02f59a82e75710676948f254124f0 100644
--- a/tests/federation/transport/test_knocking.py
+++ b/tests/federation/transport/test_knocking.py
@@ -23,10 +23,10 @@ from synapse.server import HomeServer
 from synapse.types import RoomAlias
 
 from tests.test_utils import event_injection
-from tests.unittest import FederatingHomeserverTestCase, TestCase
+from tests.unittest import FederatingHomeserverTestCase, HomeserverTestCase
 
 
-class KnockingStrippedStateEventHelperMixin(TestCase):
+class KnockingStrippedStateEventHelperMixin(HomeserverTestCase):
     def send_example_state_events_to_room(
         self,
         hs: "HomeServer",
@@ -49,7 +49,7 @@ class KnockingStrippedStateEventHelperMixin(TestCase):
         # To set a canonical alias, we'll need to point an alias at the room first.
         canonical_alias = "#fancy_alias:test"
         self.get_success(
-            self.store.create_room_alias_association(
+            self.hs.get_datastores().main.create_room_alias_association(
                 RoomAlias.from_string(canonical_alias), room_id, ["test"]
             )
         )
diff --git a/tests/rest/client/test_sync.py b/tests/rest/client/test_sync.py
index c9afa0f3dd05a40a35a9c0ff81c3dbe70e427116..b9047194dd634ddd2329eb410a59282ee0401aef 100644
--- a/tests/rest/client/test_sync.py
+++ b/tests/rest/client/test_sync.py
@@ -294,9 +294,7 @@ class SyncTypingTests(unittest.HomeserverTestCase):
             self.make_request("GET", sync_url % (access_token, next_batch))
 
 
-class SyncKnockTestCase(
-    unittest.HomeserverTestCase, KnockingStrippedStateEventHelperMixin
-):
+class SyncKnockTestCase(KnockingStrippedStateEventHelperMixin):
     servlets = [
         synapse.rest.admin.register_servlets,
         login.register_servlets,