diff --git a/clientapi/consumers/roomserver.go b/clientapi/consumers/roomserver.go
index a65281514..98202dc69 100644
--- a/clientapi/consumers/roomserver.go
+++ b/clientapi/consumers/roomserver.go
@@ -15,8 +15,10 @@
 package consumers
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
 	"github.com/matrix-org/dendrite/common"
@@ -84,7 +86,36 @@ func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 		return nil
 	}
 
-	ev := output.NewRoomEvent.Event
+	// See if the room version is present in the headers. If it isn't
+	// then we can't process the event as we don't know what the format
+	// will be
+	var roomVersion gomatrixserverlib.RoomVersion
+	for _, header := range msg.Headers {
+		if bytes.Equal(header.Key, []byte("room_version")) {
+			roomVersion = gomatrixserverlib.RoomVersion(header.Value)
+			break
+		}
+	}
+	if roomVersion == "" {
+		return errors.New("room version was not in sarama headers")
+	}
+
+	// Prepare the room event so that it has the correct field types
+	// for the room version
+	ev := gomatrixserverlib.Event{}
+	if err := ev.PrepareAs(roomVersion); err != nil {
+		log.WithFields(log.Fields{
+			"room_version": roomVersion,
+		}).WithError(err).Errorf("can't prepare event to version")
+		return err
+	}
+
+	if err := json.Unmarshal(msg.Value, &ev); err != nil {
+		// If the message was invalid, log it and move on to the next message in the stream
+		log.WithError(err).Errorf("roomserver output log: message parse failure")
+		return nil
+	}
+
 	log.WithFields(log.Fields{
 		"event_id": ev.EventID(),
 		"room_id":  ev.RoomID(),