diff -u b/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php b/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php
--- b/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php
+++ b/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php
@@ -133,7 +133,7 @@
    * {@inheritdoc}
    */
   protected function getSourceBasePath() {
-    return __DIR__ . '/files';
+    return '';
   }
 
   /**