diff --git a/roomserver/api/output.go b/roomserver/api/output.go
index d57f3b04c..53f4decc0 100644
--- a/roomserver/api/output.go
+++ b/roomserver/api/output.go
@@ -24,6 +24,8 @@ type OutputType string
 const (
 	// OutputTypeNewRoomEvent indicates that the event is an OutputNewRoomEvent
 	OutputTypeNewRoomEvent OutputType = "new_room_event"
+	// OutputTypeOldRoomEvent indicates that the event is an OutputOldRoomEvent
+	OutputTypeOldRoomEvent OutputType = "old_room_event"
 	// OutputTypeNewInviteEvent indicates that the event is an OutputNewInviteEvent
 	OutputTypeNewInviteEvent OutputType = "new_invite_event"
 	// OutputTypeRetireInviteEvent indicates that the event is an OutputRetireInviteEvent
@@ -58,6 +60,8 @@ type OutputEvent struct {
 	Type OutputType `json:"type"`
 	// The content of event with type OutputTypeNewRoomEvent
 	NewRoomEvent *OutputNewRoomEvent `json:"new_room_event,omitempty"`
+	// The content of event with type OutputTypeOldRoomEvent
+	OldRoomEvent *OutputOldRoomEvent `json:"old_room_event,omitempty"`
 	// The content of event with type OutputTypeNewInviteEvent
 	NewInviteEvent *OutputNewInviteEvent `json:"new_invite_event,omitempty"`
 	// The content of event with type OutputTypeRetireInviteEvent
@@ -178,6 +182,14 @@ func (ore *OutputNewRoomEvent) AddsState() []gomatrixserverlib.HeaderedEvent {
 	return append(ore.AddStateEvents, ore.Event)
 }
 
+// An OutputOldRoomEvent is written when the roomserver receives an old event.
+// Old events do not update forward extremities or the current room state,
+// therefore they must not be treated as if they do.
+type OutputOldRoomEvent struct {
+	// The Event.
+	Event gomatrixserverlib.HeaderedEvent `json:"event"`
+}
+
 // An OutputNewInviteEvent is written whenever an invite becomes active.
 // Invite events can be received outside of an existing room so have to be
 // tracked separately from the room events themselves.
diff --git a/roomserver/internal/input/input_events.go b/roomserver/internal/input/input_events.go
index 1034f62b5..67031609f 100644
--- a/roomserver/internal/input/input_events.go
+++ b/roomserver/internal/input/input_events.go
@@ -136,7 +136,8 @@ func (r *Inputer) processRoomEvent(
 		return event.EventID(), rejectionErr
 	}
 
-	if input.Kind == api.KindNew {
+	switch input.Kind {
+	case api.KindNew:
 		if err = r.updateLatestEvents(
 			ctx,                 // context
 			roomInfo,            // room info for the room being updated
@@ -148,6 +149,18 @@ func (r *Inputer) processRoomEvent(
 		); err != nil {
 			return "", fmt.Errorf("r.updateLatestEvents: %w", err)
 		}
+	case api.KindOld:
+		err = r.WriteOutputEvents(event.RoomID(), []api.OutputEvent{
+			{
+				Type: api.OutputTypeOldRoomEvent,
+				OldRoomEvent: &api.OutputOldRoomEvent{
+					Event: headered,
+				},
+			},
+		})
+		if err != nil {
+			return "", fmt.Errorf("r.WriteOutputEvents (old): %w", err)
+		}
 	}
 
 	// processing this event resulted in an event (which may not be the one we're processing)
@@ -165,7 +178,7 @@ func (r *Inputer) processRoomEvent(
 			},
 		})
 		if err != nil {
-			return "", fmt.Errorf("r.WriteOutputEvents: %w", err)
+			return "", fmt.Errorf("r.WriteOutputEvents (redactions): %w", err)
 		}
 	}