diff --git a/src/cloudron.js b/src/cloudron.js
index 3b3ef9092..1967ad56b 100644
--- a/src/cloudron.js
+++ b/src/cloudron.js
@@ -558,7 +558,7 @@ function backupBoxWithAppBackupIds(appBackupIds, callback) {
 
     backups.getBackupUrl(null /* app */, appBackupIds, function (error, result) {
         if (error && error.reason === BackupsError.EXTERNAL_ERROR) return callback(new CloudronError(CloudronError.EXTERNAL_ERROR, error.message));
-        if (error) return callback(new CloudronError.INTERNAL_ERROR, error);
+        if (error) return callback(new CloudronError(CloudronError.INTERNAL_ERROR, error));
 
         debug('backup: url %s', result.url);