diff --git a/clientapi/routing/login.go b/clientapi/routing/login.go
index 0105f6d21..523a8e250 100644
--- a/clientapi/routing/login.go
+++ b/clientapi/routing/login.go
@@ -73,7 +73,7 @@ func Login(
 			return util.JSONResponse{
 				Code: http.StatusOK,
 				JSON: loginResponse{
-					UserID:      login.Username(),
+					UserID:      userutil.MakeUserID(login.Username(), cfg.Matrix.ServerName),
 					AccessToken: "",
 					HomeServer:  cfg.Matrix.ServerName,
 					DeviceID:    "",
diff --git a/userapi/storage/shared/storage.go b/userapi/storage/shared/storage.go
index 4e28f7b5a..294f96918 100644
--- a/userapi/storage/shared/storage.go
+++ b/userapi/storage/shared/storage.go
@@ -562,7 +562,7 @@ func (d *Database) CreateDevice(
 	ctx context.Context, localpart string, deviceID *string, accessToken string,
 	displayName *string, ipAddr, userAgent string,
 ) (dev *api.Device, returnErr error) {
-	if deviceID != nil {
+	if deviceID != nil && *deviceID != "" {
 		returnErr = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 			var err error
 			// Revoke existing tokens for this device