diff --git a/question/engine/tests/helpers.php b/question/engine/tests/helpers.php
index 14425d6ec53..c2993b132bd 100644
--- a/question/engine/tests/helpers.php
+++ b/question/engine/tests/helpers.php
@@ -414,21 +414,14 @@ abstract class testing_db_record_builder {
  * @copyright  2009 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class data_loading_method_test_base extends advanced_testcase {
+abstract class data_loading_method_test_base extends advanced_testcase {
     public function build_db_records(array $table) {
         return testing_db_record_builder::build_db_records($table);
     }
-    public function test_must_have_methods() {
-        // each test case must have at least one method..
-    }
 }
 
 
-class question_testcase extends advanced_testcase {
-
-    public function test_must_have_methods() {
-        // each test case must have at least one method..
-    }
+abstract class question_testcase extends advanced_testcase {
 
     public function assert($expectation, $compare, $message = '') {
         $message = (isset($expectation->message) and $expectation->message !== '') ? $expectation->message : $message;
@@ -618,7 +611,7 @@ class question_no_pattern_expectation {
  * @copyright  2009 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class qbehaviour_walkthrough_test_base extends question_testcase {
+abstract class qbehaviour_walkthrough_test_base extends question_testcase {
     /** @var question_display_options */
     protected $displayoptions;
     /** @var question_usage_by_activity */
diff --git a/question/engine/upgrade/tests/helper.php b/question/engine/upgrade/tests/helper.php
index 3ba39f76cc4..21dce02b985 100644
--- a/question/engine/upgrade/tests/helper.php
+++ b/question/engine/upgrade/tests/helper.php
@@ -93,7 +93,7 @@ class test_question_engine_upgrade_question_loader extends question_engine_upgra
  * @copyright  2009 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class question_attempt_upgrader_test_base extends advanced_testcase {
+abstract class question_attempt_upgrader_test_base extends advanced_testcase {
     protected $updater;
     protected $loader;
 
@@ -109,10 +109,6 @@ class question_attempt_upgrader_test_base extends advanced_testcase {
         parent::tearDown();
     }
 
-    public function test_must_have_methods() {
-        // each test case must have at least one method..
-    }
-
     /**
      * Clear text, bringing independence of html2text results
      *
diff --git a/question/engine/upgrade/upgradelib.php b/question/engine/upgrade/upgradelib.php
index ba849047cbf..531889dbe77 100644
--- a/question/engine/upgrade/upgradelib.php
+++ b/question/engine/upgrade/upgradelib.php
@@ -453,8 +453,8 @@ class question_engine_attempt_upgrader {
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class question_engine_upgrade_question_loader {
-    private $cache = array();
-    private $datasetcache = array();
+    protected $cache = array();
+    protected $datasetcache = array();
 
     public function __construct($logger) {
         $this->logger = $logger;