diff --git a/tests/extension/modules_test.php b/tests/extension/modules_test.php
index 9849ad2ca4..675fb1f4a0 100644
--- a/tests/extension/modules_test.php
+++ b/tests/extension/modules_test.php
@@ -42,6 +42,11 @@ class phpbb_extension_modules_test extends phpbb_test_case
 
 	public function test_get_module_infos()
 	{
+		global $phpbb_root_path;
+
+		// Correctly set the root path for this test to this directory, so the classes can be found
+		$phpbb_root_path = dirname(__FILE__) . '/';
+
 		$this->acp_modules->module_class = 'acp';
 		$acp_modules = $this->acp_modules->get_module_infos();
 		$this->assertEquals(array(