diff --git a/core/modules/simpletest/simpletest.module b/core/modules/simpletest/simpletest.module
index 97caa11..b962534 100644
--- a/core/modules/simpletest/simpletest.module
+++ b/core/modules/simpletest/simpletest.module
@@ -725,7 +725,7 @@ function simpletest_phpunit_get_available_tests() {
   $test_classes = array();
   foreach ($test_suite AS $test) {
     $name = get_class($test);
-    if (!array_key_exists($name, $test_classes)) {
+    if (!array_key_exists($name, $test_classes) && method_exists($test, 'getInfo')) {
       $test_classes[$name] =  $test->getInfo();
     }
   }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
index 882ae96..5d5fb63 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
@@ -104,10 +104,10 @@ function testContext() {
     $this->assertEqual($user->label(), $plugin->getTitle());
 
     // Test the getContextDefinitions() method.
-    $this->assertIdentical($plugin->getContextDefinitions(), array('user' => array('class' => 'Drupal\user\Plugin\Core\Entity\User')));
+    $this->assertIdentical($plugin->getContextDefinitions(), array('user' => array('class' => 'Drupal\user\UserInterface')));
 
     // Test the getContextDefinition() method for a valid context.
-    $this->assertEqual($plugin->getContextDefinition('user'), array('class' => 'Drupal\user\Plugin\Core\Entity\User'));
+    $this->assertEqual($plugin->getContextDefinition('user'), array('class' => 'Drupal\user\UserInterface'));
 
     // Test the getContextDefinition() method for an invalid context.
     try {
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php
index 157e583..a897160 100644
--- a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/MockBlockManager.php
@@ -72,7 +72,7 @@ public function __construct() {
       'label' => t('User name'),
       'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockUserNameBlock',
       'context' => array(
-        'user' => array('class' => 'Drupal\user\Plugin\Core\Entity\User')
+        'user' => array('class' => 'Drupal\user\UserInterface')
       ),
     ));
 
@@ -90,7 +90,7 @@ public function __construct() {
       'label' => t('Complex context'),
       'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockComplexContextBlock',
       'context' => array(
-        'user' => array('class' => 'Drupal\user\Plugin\Core\Entity\User'),
+        'user' => array('class' => 'Drupal\user\UserInterface'),
         'node' => array('class' => 'Drupal\Core\Entity\EntityBCDecorator'),
       ),
     ));