diff --git a/tests/template/extension_test.php b/tests/template/extension_test.php
index 7bdd6ba591..b350a0d905 100644
--- a/tests/template/extension_test.php
+++ b/tests/template/extension_test.php
@@ -29,6 +29,7 @@ class phpbb_template_extension_test extends phpbb_template_template_test_case
 		$this->lang = $lang = new \phpbb\language\language($lang_loader);
 		$this->user = new \phpbb\user($lang, '\phpbb\datetime');
 		$this->user->style['style_path'] = 'chameleon';
+		$this->user->style['style_parent_id'] = 0;
 
 		global $auth, $request, $symfony_request, $user;
 		$user = new phpbb_mock_user();