diff --git a/synapse/replication/http/federation.py b/synapse/replication/http/federation.py
index 64a79da162..2e16c69666 100644
--- a/synapse/replication/http/federation.py
+++ b/synapse/replication/http/federation.py
@@ -17,7 +17,7 @@ import logging
 
 from twisted.internet import defer
 
-from synapse.events import FrozenEvent
+from synapse.events import event_type_from_format_version
 from synapse.events.snapshot import EventContext
 from synapse.http.servlet import parse_json_object_from_request
 from synapse.replication.http._base import ReplicationEndpoint
@@ -70,6 +70,7 @@ class ReplicationFederationSendEventsRestServlet(ReplicationEndpoint):
 
             event_payloads.append({
                 "event": event.get_pdu_json(),
+                "event_format_version": event.format_version,
                 "internal_metadata": event.internal_metadata.get_dict(),
                 "rejected_reason": event.rejected_reason,
                 "context": serialized_context,
@@ -94,9 +95,12 @@ class ReplicationFederationSendEventsRestServlet(ReplicationEndpoint):
             event_and_contexts = []
             for event_payload in event_payloads:
                 event_dict = event_payload["event"]
+                format_ver = content["event_format_version"]
                 internal_metadata = event_payload["internal_metadata"]
                 rejected_reason = event_payload["rejected_reason"]
-                event = FrozenEvent(event_dict, internal_metadata, rejected_reason)
+
+                EventType = event_type_from_format_version(format_ver)
+                event = EventType(event_dict, internal_metadata, rejected_reason)
 
                 context = yield EventContext.deserialize(
                     self.store, event_payload["context"],
diff --git a/synapse/replication/http/send_event.py b/synapse/replication/http/send_event.py
index 5b52c91650..3635015eda 100644
--- a/synapse/replication/http/send_event.py
+++ b/synapse/replication/http/send_event.py
@@ -17,7 +17,7 @@ import logging
 
 from twisted.internet import defer
 
-from synapse.events import FrozenEvent
+from synapse.events import event_type_from_format_version
 from synapse.events.snapshot import EventContext
 from synapse.http.servlet import parse_json_object_from_request
 from synapse.replication.http._base import ReplicationEndpoint
@@ -74,6 +74,7 @@ class ReplicationSendEventRestServlet(ReplicationEndpoint):
 
         payload = {
             "event": event.get_pdu_json(),
+            "event_format_version": event.format_version,
             "internal_metadata": event.internal_metadata.get_dict(),
             "rejected_reason": event.rejected_reason,
             "context": serialized_context,
@@ -90,9 +91,12 @@ class ReplicationSendEventRestServlet(ReplicationEndpoint):
             content = parse_json_object_from_request(request)
 
             event_dict = content["event"]
+            format_ver = content["event_format_version"]
             internal_metadata = content["internal_metadata"]
             rejected_reason = content["rejected_reason"]
-            event = FrozenEvent(event_dict, internal_metadata, rejected_reason)
+
+            EventType = event_type_from_format_version(format_ver)
+            event = EventType(event_dict, internal_metadata, rejected_reason)
 
             requester = Requester.deserialize(self.store, content["requester"])
             context = yield EventContext.deserialize(self.store, content["context"])
diff --git a/synapse/storage/events_worker.py b/synapse/storage/events_worker.py
index 599f892858..0a0ca58fc4 100644
--- a/synapse/storage/events_worker.py
+++ b/synapse/storage/events_worker.py
@@ -23,7 +23,7 @@ from twisted.internet import defer
 
 from synapse.api.constants import EventFormatVersions
 from synapse.api.errors import NotFoundError
-from synapse.events import FrozenEvent
+from synapse.events import FrozenEvent, event_type_from_format_version  # noqa: F401
 # these are only included to make the type annotations work
 from synapse.events.snapshot import EventContext  # noqa: F401
 from synapse.events.utils import prune_event
@@ -412,11 +412,7 @@ class EventsWorkerStore(SQLBaseStore):
                 # of a event format version, so it must be a V1 event.
                 format_version = EventFormatVersions.V1
 
-            # TODO: When we implement new event formats we'll need to use a
-            # different event python type
-            assert format_version == EventFormatVersions.V1
-
-            original_ev = FrozenEvent(
+            original_ev = event_type_from_format_version(format_version)(
                 event_dict=d,
                 internal_metadata_dict=internal_metadata,
                 rejected_reason=rejected_reason,