diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index b91894f9c0..a3864d3041 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -94,6 +94,8 @@ class phpbb_functional_test_case extends phpbb_test_case
 
 		foreach (static::setup_extensions() as $extension)
 		{
+			$this->purge_cache();
+
 			$sql = 'SELECT ext_active
 				FROM ' . EXT_TABLE . "
 				WHERE ext_name = '" . $db->sql_escape($extension). "'";