diff --git a/federationapi/consumers/roomserver.go b/federationapi/consumers/roomserver.go
index 19bf3730b..6dd2fd345 100644
--- a/federationapi/consumers/roomserver.go
+++ b/federationapi/consumers/roomserver.go
@@ -411,7 +411,7 @@ func JoinedHostsFromEvents(ctx context.Context, evs []gomatrixserverlib.PDU, rsA
 		if err != nil {
 			return nil, err
 		}
-		userID, err := rsAPI.QueryUserIDForSender(ctx, *validRoomID, ev.SenderID())
+		userID, err := rsAPI.QueryUserIDForSender(ctx, *validRoomID, spec.SenderID(*ev.StateKey()))
 		if err != nil {
 			return nil, err
 		}
diff --git a/roomserver/internal/perform/perform_join.go b/roomserver/internal/perform/perform_join.go
index 092567ca6..3883a5b96 100644
--- a/roomserver/internal/perform/perform_join.go
+++ b/roomserver/internal/perform/perform_join.go
@@ -204,7 +204,8 @@ func (r *Joiner) performJoinRoomByID(
 			senderID, err = r.Queryer.QuerySenderIDForUser(ctx, *roomID, *userID)
 			if err == nil {
 				checkInvitePending = true
-			} else {
+			}
+			if senderID == "" {
 				// create user room key if needed
 				key, keyErr := r.RSAPI.GetOrCreateUserRoomPrivateKey(ctx, *userID, *roomID)
 				if keyErr != nil {