diff -u b/tests/libraries.drush.test b/tests/libraries.drush.test
--- b/tests/libraries.drush.test
+++ b/tests/libraries.drush.test
@@ -65,7 +65,7 @@
       $info = libraries_detect($library);
       $this->assertFalse($info['installed']);
 
-      $this->manager->download([$library], $options);
+      $this->manager->download(array($library), $options);
       drupal_flush_all_caches();
 
       $info = libraries_detect($library);