1 files changed, 1 insertions, 3 deletions
diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py
index ba16f22c91..b448da6710 100644
--- a/synapse/replication/http/_base.py
+++ b/synapse/replication/http/_base.py
@@ -33,7 +33,7 @@ from synapse.util.stringutils import random_string
 logger = logging.getLogger(__name__)
 
 
-class ReplicationEndpoint:
+class ReplicationEndpoint(metaclass=abc.ABCMeta):
     """Helper base class for defining new replication HTTP endpoints.
 
     This creates an endpoint under `/_synapse/replication/:NAME/:PATH_ARGS..`
@@ -72,8 +72,6 @@ class ReplicationEndpoint:
             is received.
     """
 
-    __metaclass__ = abc.ABCMeta
-
     NAME = abc.abstractproperty()  # type: str  # type: ignore
     PATH_ARGS = abc.abstractproperty()  # type: Tuple[str, ...]  # type: ignore
     METHOD = "POST"