1 files changed, 6 insertions, 1 deletions
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index 0cd424e12a..f56344a3b9 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 import logging
 from collections import namedtuple
+from typing import TYPE_CHECKING
 
 from synapse.api.constants import MAX_DEPTH, EventContentFields, EventTypes, Membership
 from synapse.api.errors import Codes, SynapseError
@@ -25,11 +26,15 @@ from synapse.events.utils import prune_event, validate_canonicaljson
 from synapse.http.servlet import assert_params_in_dict
 from synapse.types import JsonDict, get_domain_from_id
 
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+
 logger = logging.getLogger(__name__)
 
 
 class FederationBase:
-    def __init__(self, hs):
+    def __init__(self, hs: "HomeServer"):
         self.hs = hs
 
         self.server_name = hs.hostname