diff --git a/syncapi/streams/stream_pdu.go b/syncapi/streams/stream_pdu.go
index 800915159..0d033095d 100644
--- a/syncapi/streams/stream_pdu.go
+++ b/syncapi/streams/stream_pdu.go
@@ -294,17 +294,11 @@ func (p *PDUStreamProvider) addRoomDeltaToResponse(
 		}
 	}
 
-	// Work out how many members are in the room.
-	joinedCount, _ := p.DB.MembershipCount(ctx, delta.RoomID, gomatrixserverlib.Join, latestPosition)
-	invitedCount, _ := p.DB.MembershipCount(ctx, delta.RoomID, gomatrixserverlib.Invite, latestPosition)
-
 	switch delta.Membership {
 	case gomatrixserverlib.Join:
 		jr := types.NewJoinResponse()
 		if hasMembershipChange {
-			jr.Summary.JoinedMemberCount = &joinedCount
-			jr.Summary.InvitedMemberCount = &invitedCount
-			p.addHeroes(ctx, jr, delta.RoomID, device.UserID)
+			p.addRoomSummary(ctx, jr, delta.RoomID, device.UserID, latestPosition)
 		}
 		jr.Timeline.PrevBatch = &prevBatch
 		jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
@@ -337,7 +331,14 @@ func (p *PDUStreamProvider) addRoomDeltaToResponse(
 	return latestPosition, nil
 }
 
-func (p *PDUStreamProvider) addHeroes(ctx context.Context, jr *types.JoinResponse, roomID, userID string) {
+func (p *PDUStreamProvider) addRoomSummary(ctx context.Context, jr *types.JoinResponse, roomID, userID string, latestPosition types.StreamPosition) {
+	// Work out how many members are in the room.
+	joinedCount, _ := p.DB.MembershipCount(ctx, roomID, gomatrixserverlib.Join, latestPosition)
+	invitedCount, _ := p.DB.MembershipCount(ctx, roomID, gomatrixserverlib.Invite, latestPosition)
+
+	jr.Summary.JoinedMemberCount = &joinedCount
+	jr.Summary.InvitedMemberCount = &invitedCount
+
 	fetchStates := []gomatrixserverlib.StateKeyTuple{
 		{EventType: gomatrixserverlib.MRoomName},
 		{EventType: gomatrixserverlib.MRoomCanonicalAlias},
@@ -453,10 +454,7 @@ func (p *PDUStreamProvider) getJoinResponseForCompleteSync(
 		prevBatch.Decrement()
 	}
 
-	// Work out how many members are in the room.
-	joinedCount, _ := p.DB.MembershipCount(ctx, roomID, gomatrixserverlib.Join, r.From)
-	invitedCount, _ := p.DB.MembershipCount(ctx, roomID, gomatrixserverlib.Invite, r.From)
-	p.addHeroes(ctx, jr, roomID, device.UserID)
+	p.addRoomSummary(ctx, jr, roomID, device.UserID, r.From)
 
 	// We don't include a device here as we don't need to send down
 	// transaction IDs for complete syncs, but we do it anyway because Sytest demands it for:
@@ -477,8 +475,6 @@ func (p *PDUStreamProvider) getJoinResponseForCompleteSync(
 		}
 	}
 
-	jr.Summary.JoinedMemberCount = &joinedCount
-	jr.Summary.InvitedMemberCount = &invitedCount
 	jr.Timeline.PrevBatch = prevBatch
 	jr.Timeline.Events = gomatrixserverlib.HeaderedToClientEvents(recentEvents, gomatrixserverlib.FormatSync)
 	jr.Timeline.Limited = limited