diff --git a/tests/functional/search/mysql_test.php b/tests/functional/search/mysql_test.php
index db6f688e2a..0693c69968 100644
--- a/tests/functional/search/mysql_test.php
+++ b/tests/functional/search/mysql_test.php
@@ -14,5 +14,5 @@ require_once dirname(__FILE__) . '/base.php';
 */
 class phpbb_functional_search_mysql_test extends phpbb_functional_search_base
 {
-	protected $search_backend = 'phpbb_search_fulltext_mysql';
+	protected $search_backend = '\phpbb\search\fulltext_mysql';
 }
diff --git a/tests/functional/search/native_test.php b/tests/functional/search/native_test.php
index 63e7085308..ce568df616 100644
--- a/tests/functional/search/native_test.php
+++ b/tests/functional/search/native_test.php
@@ -14,7 +14,7 @@ require_once dirname(__FILE__) . '/base.php';
 */
 class phpbb_functional_search_native_test extends phpbb_functional_search_base
 {
-	protected $search_backend = 'phpbb_search_fulltext_native';
+	protected $search_backend = '\phpbb\search\fulltext_native';
 
 	protected function assert_search_not_found($keywords)
 	{
diff --git a/tests/functional/search/postgres_test.php b/tests/functional/search/postgres_test.php
index f733238c8f..487b8aeebb 100644
--- a/tests/functional/search/postgres_test.php
+++ b/tests/functional/search/postgres_test.php
@@ -14,7 +14,7 @@ require_once dirname(__FILE__) . '/base.php';
 */
 class phpbb_functional_search_postgres_test extends phpbb_functional_search_base
 {
-	protected $search_backend = 'phpbb_search_fulltext_postgres';
+	protected $search_backend = '\phpbb\search\fulltext_postgres';
 
 	protected function assert_search_not_found($keywords)
 	{
diff --git a/tests/functional/search/sphinx_test.php b/tests/functional/search/sphinx_test.php
index 9db4138714..ef2522f9ed 100644
--- a/tests/functional/search/sphinx_test.php
+++ b/tests/functional/search/sphinx_test.php
@@ -14,7 +14,7 @@ require_once dirname(__FILE__) . '/base.php';
 */
 class phpbb_functional_search_sphinx_test extends phpbb_functional_search_base
 {
-	protected $search_backend = 'phpbb_search_fulltext_sphinx';
+	protected $search_backend = '\phpbb\search\fulltext_sphinx';
 
 	public function test_search_backend()
 	{