diff --git a/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go b/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go
index 911ccd0d9..ca46828f9 100644
--- a/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go
+++ b/src/github.com/matrix-org/dendrite/syncapi/consumers/roomserver.go
@@ -38,12 +38,6 @@ type OutputRoomEvent struct {
 	query              api.RoomserverQueryAPI
 }
 
-type prevEventRef struct {
-	PrevContent json.RawMessage `json:"prev_content"`
-	PrevID      string          `json:"replaces_state"`
-	UserID      string          `json:"prev_sender"`
-}
-
 // NewOutputRoomEvent creates a new OutputRoomEvent consumer. Call Start() to begin consuming from room servers.
 func NewOutputRoomEvent(
 	cfg *config.Dendrite,
@@ -267,10 +261,10 @@ func (s *OutputRoomEvent) updateStateEvent(event gomatrixserverlib.Event) (gomat
 		return event, nil
 	}
 
-	prev := prevEventRef{
+	prev := types.PrevEventRef{
 		PrevContent: prevEvent.Content(),
 		PrevID:      prevEvent.EventID(),
-		UserID:      prevEvent.Sender(),
+		PrevSender:  prevEvent.Sender(),
 	}
 
 	return event.SetUnsigned(prev)
diff --git a/src/github.com/matrix-org/dendrite/syncapi/types/types.go b/src/github.com/matrix-org/dendrite/syncapi/types/types.go
index adc764c32..cf737a408 100644
--- a/src/github.com/matrix-org/dendrite/syncapi/types/types.go
+++ b/src/github.com/matrix-org/dendrite/syncapi/types/types.go
@@ -15,6 +15,7 @@
 package types
 
 import (
+	"encoding/json"
 	"strconv"
 
 	"github.com/matrix-org/gomatrixserverlib"
@@ -28,6 +29,13 @@ func (sp StreamPosition) String() string {
 	return strconv.FormatInt(int64(sp), 10)
 }
 
+// PrevEventRef represents a reference to a previous event in a state event upgrade
+type PrevEventRef struct {
+	PrevContent json.RawMessage `json:"prev_content"`
+	PrevID      string          `json:"replaces_state"`
+	PrevSender  string          `json:"prev_sender"`
+}
+
 // Response represents a /sync API response. See https://matrix.org/docs/spec/client_server/r0.2.0.html#get-matrix-client-r0-sync
 type Response struct {
 	NextBatch   string `json:"next_batch"`