diff --git a/lib/tests/session_redis_test.php b/lib/tests/session_redis_test.php
index 8b32e759fed..316b41ea60b 100644
--- a/lib/tests/session_redis_test.php
+++ b/lib/tests/session_redis_test.php
@@ -38,6 +38,7 @@ defined('MOODLE_INTERNAL') || die();
  * @author    Russell Smith <mr-russ@smith2001.net>
  * @copyright 2016 Russell Smith
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @runTestsInSeparateProcesses
  */
 class core_session_redis_testcase extends advanced_testcase {