diff --git a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFastFileStorageTest.php b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFastFileStorageTest.php
index abb6db9..d2a3e16 100644
--- a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFastFileStorageTest.php
+++ b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFastFileStorageTest.php
@@ -10,7 +10,7 @@
 /**
  * Tests the directory mtime based PHP loader implementation.
  */
-class MTimeProtectedFastFileStorageTest extends MTimeProtectedFileStorageTest {
+class MTimeProtectedFastFileStorageTest extends MTimeProtectedFileStorageBase {
 
   /**
    * The expected test results for the security test.
@@ -22,10 +22,13 @@ class MTimeProtectedFastFileStorageTest extends MTimeProtectedFileStorageTest {
   protected $expected = array(TRUE, FALSE);
 
   /**
-   * Test this class.
+   * The PHP storage class to test.
    */
   protected $storageClass = 'Drupal\Component\PhpStorage\MTimeProtectedFastFileStorage';
 
+  /**
+   * {@inheritdoc}
+   */
   public static function getInfo() {
     return array(
       'name' => 'MTime protected fast file storage',
@@ -33,4 +36,5 @@ public static function getInfo() {
       'group' => 'PHP Storage',
     );
   }
+
 }
diff --git a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageTest.php b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageBase.php
similarity index 82%
copy from core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageTest.php
copy to core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageBase.php
index 214b1a7..216204a 100644
--- a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageTest.php
+++ b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageBase.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Definition of Drupal\Tests\Component\PhpStorage\MTimeProtectedFileStorageTest.
+ * Contains \Drupal\Tests\Component\PhpStorage\MTimeProtectedFileStorageBase.
  */
 
 namespace Drupal\Tests\Component\PhpStorage;
@@ -11,30 +11,32 @@
 use Drupal\Component\Utility\Settings;
 
 /**
- * Tests the directory mtime based PHP loader implementation.
+ * Base test class for MTime protected storage.
  */
-class MTimeProtectedFileStorageTest extends PhpStorageTestBase {
+abstract class MTimeProtectedFileStorageBase extends PhpStorageTestBase {
 
   /**
-   * The expected test results for the security test.
+   * The PHP storage class to test.
    *
-   * The default implementation protects against even the filemtime change so
-   * both iterations will return FALSE.
+   * This should be overridden by extending classes.
    */
-  protected $expected = array(FALSE, FALSE);
+  protected $storageClass;
 
-  protected $storageClass = 'Drupal\Component\PhpStorage\MTimeProtectedFileStorage';
-
-  public static function getInfo() {
-    return array(
-      'name' => 'MTime protected file storage',
-      'description' => 'Tests the MTimeProtectedFileStorage implementation.',
-      'group' => 'PHP Storage',
-    );
-  }
+  /**
+   * The secret string to use for file creation.
+   *
+   * @var string
+   */
+  protected $secret;
 
+  /**
+   * {@inheritdoc}
+   */
   function setUp() {
     parent::setUp();
+
+    $this->storageFactory = new PhpStorageFactory;
+
     $this->secret = $this->randomName();
     $settings['php_storage']['simpletest'] = array(
       'class' => $this->storageClass,
@@ -112,4 +114,5 @@ function testSecurity() {
       $this->assertSame($GLOBALS['hacked'], $this->expected[$i]);
     }
   }
+
 }
diff --git a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageTest.php b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageTest.php
index 214b1a7..6e954f7 100644
--- a/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageTest.php
+++ b/core/tests/Drupal/Tests/Component/PhpStorage/MTimeProtectedFileStorageTest.php
@@ -7,13 +7,10 @@
 
 namespace Drupal\Tests\Component\PhpStorage;
 
-use Drupal\Component\PhpStorage\PhpStorageFactory;
-use Drupal\Component\Utility\Settings;
-
 /**
  * Tests the directory mtime based PHP loader implementation.
  */
-class MTimeProtectedFileStorageTest extends PhpStorageTestBase {
+class MTimeProtectedFileStorageTest extends MTimeProtectedFileStorageBase {
 
   /**
    * The expected test results for the security test.
@@ -23,8 +20,14 @@ class MTimeProtectedFileStorageTest extends PhpStorageTestBase {
    */
   protected $expected = array(FALSE, FALSE);
 
+  /**
+   * The PHP storage class to test.
+   */
   protected $storageClass = 'Drupal\Component\PhpStorage\MTimeProtectedFileStorage';
 
+  /**
+   * {@inheritdoc}
+   */
   public static function getInfo() {
     return array(
       'name' => 'MTime protected file storage',
@@ -33,83 +36,4 @@ public static function getInfo() {
     );
   }
 
-  function setUp() {
-    parent::setUp();
-    $this->secret = $this->randomName();
-    $settings['php_storage']['simpletest'] = array(
-      'class' => $this->storageClass,
-      'directory' => sys_get_temp_dir() . '/php',
-      'secret' => $this->secret,
-    );
-    new Settings($settings);
-  }
-
-  /**
-   * Tests basic load/save/delete operations.
-   */
-  function testCRUD() {
-    $php = $this->storageFactory->get('simpletest');
-    $this->assertSame(get_class($php), $this->storageClass);
-    $this->assertCRUD($php);
-  }
-
-  /**
-   * Tests the security of the MTimeProtectedFileStorage implementation.
-   *
-   * We test two attacks: first changes the file mtime, then the directory
-   * mtime too.
-   *
-   * We need to delay over 1 second for mtime test.
-   * @medium
-   */
-  function testSecurity() {
-    $php = $this->storageFactory->get('simpletest');
-    $name = 'simpletest.php';
-    $php->save($name, '<?php');
-    $expected_root_directory = sys_get_temp_dir() . '/php/simpletest';
-    $expected_directory = $expected_root_directory . '/' . $name;
-    $directory_mtime = filemtime($expected_directory);
-    $expected_filename = $expected_directory . '/' . hash_hmac('sha256', $name, $this->secret . $directory_mtime) . '.php';
-
-    // Ensure the file exists and that it and the containing directory have
-    // minimal permissions. fileperms() can return high bits unrelated to
-    // permissions, so mask with 0777.
-    $this->assertTrue(file_exists($expected_filename));
-    $this->assertSame(fileperms($expected_filename) & 0777, 0444);
-    $this->assertSame(fileperms($expected_directory) & 0777, 0777);
-
-    // Ensure the root directory for the bin has a .htaccess file denying web
-    // access.
-    $this->assertSame(file_get_contents($expected_root_directory . '/.htaccess'), "SetHandler Drupal_Security_Do_Not_Remove_See_SA_2006_006\nDeny from all\nOptions None\nOptions +FollowSymLinks");
-
-    // Ensure that if the file is replaced with an untrusted one (due to another
-    // script's file upload vulnerability), it does not get loaded. Since mtime
-    // granularity is 1 second, we cannot prevent an attack that happens within
-    // a second of the initial save().
-    sleep(1);
-    for ($i = 0; $i < 2; $i++) {
-      $php = $this->storageFactory->get('simpletest');
-      $GLOBALS['hacked'] = FALSE;
-      $untrusted_code = "<?php\n" . '$GLOBALS["hacked"] = TRUE;';
-      chmod($expected_directory, 0700);
-      chmod($expected_filename, 0700);
-      if ($i) {
-        // Now try to write the file in such a way that the directory mtime
-        // changes and invalidates the hash.
-        file_put_contents($expected_filename . '.tmp', $untrusted_code);
-        rename($expected_filename . '.tmp', $expected_filename);
-      }
-      else {
-        // On the first try do not change the directory mtime but the filemtime
-        // is now larger than the directory mtime.
-        file_put_contents($expected_filename, $untrusted_code);
-      }
-      chmod($expected_filename, 0400);
-      chmod($expected_directory, 0100);
-      $this->assertSame(file_get_contents($expected_filename), $untrusted_code);
-      $this->assertSame($php->exists($name), $this->expected[$i]);
-      $this->assertSame($php->load($name), $this->expected[$i]);
-      $this->assertSame($GLOBALS['hacked'], $this->expected[$i]);
-    }
-  }
 }
diff --git a/core/tests/Drupal/Tests/Component/PhpStorage/PhpStorageTestBase.php b/core/tests/Drupal/Tests/Component/PhpStorage/PhpStorageTestBase.php
index d7a2362..ef504ec 100644
--- a/core/tests/Drupal/Tests/Component/PhpStorage/PhpStorageTestBase.php
+++ b/core/tests/Drupal/Tests/Component/PhpStorage/PhpStorageTestBase.php
@@ -23,11 +23,12 @@
   protected $storageFactory;
 
   /**
-   * Overrides \Drupal\Tests\UnitTestCase::setUp()
+   * {@inheritdoc}
    */
   function setUp() {
     parent::setUp();
-    $this->storageFactory = new PhpStorageFactory;
+
+    $this->storageFactory = new PhpStorageFactory();
   }
 
   /**
@@ -61,4 +62,5 @@ public function assertCRUD($php) {
     // FALSE, but not trigger errors.
     $this->assertSame($php->delete($name), FALSE);
   }
+
 }