diff --git a/core/modules/migrate/src/Tests/MigrateDumpAlterInterface.php b/core/modules/migrate/src/Tests/MigrateDumpAlterInterface.php
index 9ecf825..94b8a3d 100644
--- a/core/modules/migrate/src/Tests/MigrateDumpAlterInterface.php
+++ b/core/modules/migrate/src/Tests/MigrateDumpAlterInterface.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\migrate\Tests;
 
+use Drupal\simpletest\TestBase;
+
 /**
  * Allows tests to alter dumps after they've loaded.
  *
@@ -18,10 +20,9 @@
   /**
    * Allows tests to alter dumps after they've loaded.
    *
-   * @param $database_prefix
-   *   The simpletest database prefix. Can be used to ensure uniqueness to the
-   *   specific test.
+   * @param \Drupal\simpletest\TestBase $test
+   *   The test that is being run.
    */
-  public static function migrateDumpAlter($database_prefix);
+  public static function migrateDumpAlter(TestBase $test);
 
 }
diff --git a/core/modules/migrate/src/Tests/MigrateTearDownInterface.php b/core/modules/migrate/src/Tests/MigrateTearDownInterface.php
deleted file mode 100644
index 06f68ac..0000000
--- a/core/modules/migrate/src/Tests/MigrateTearDownInterface.php
+++ /dev/null
@@ -1,20 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\migrate\Tests\MigrateTearDownInterface.
- */
-
-namespace Drupal\migrate\Tests;
-
-/**
- * Allows tests to cleanup.
- */
-interface MigrateTearDownInterface {
-
-  /**
-   * Allows tests to cleanup.
-   */
-  public static function migrateTearDown();
-
-}
diff --git a/core/modules/migrate/src/Tests/MigrateTestBase.php b/core/modules/migrate/src/Tests/MigrateTestBase.php
index ec60ad9..a4c154a 100644
--- a/core/modules/migrate/src/Tests/MigrateTestBase.php
+++ b/core/modules/migrate/src/Tests/MigrateTestBase.php
@@ -66,9 +66,6 @@ protected function setUp() {
    */
   protected function tearDown() {
     Database::removeConnection('migrate');
-    if ($this instanceof MigrateTearDownInterface) {
-      static::migrateTearDown();
-    }
     parent::tearDown();
   }
 
@@ -83,7 +80,7 @@ protected function tearDown() {
   protected function prepare(MigrationInterface $migration, array $files = array()) {
     $this->loadDumps($files);
     if ($this instanceof MigrateDumpAlterInterface) {
-      static::migrateDumpAlter($this->databasePrefix);
+      static::migrateDumpAlter($this);
     }
   }
 
diff --git a/core/modules/migrate_drupal/src/Tests/MigrateFullDrupalTestBase.php b/core/modules/migrate_drupal/src/Tests/MigrateFullDrupalTestBase.php
index 2796f1e..09dd3cd 100644
--- a/core/modules/migrate_drupal/src/Tests/MigrateFullDrupalTestBase.php
+++ b/core/modules/migrate_drupal/src/Tests/MigrateFullDrupalTestBase.php
@@ -56,7 +56,7 @@ public function testDrupal() {
     $classes = $this->getTestClassesList();
     foreach ($classes as $class) {
       if (is_subclass_of($class, '\Drupal\migrate\Tests\MigrateDumpAlterInterface')) {
-        $class::migrateDumpAlter($this->databasePrefix);
+        $class::migrateDumpAlter($this);
       }
     }
 
diff --git a/core/modules/migrate_drupal/src/Tests/d6/MigrateFileTest.php b/core/modules/migrate_drupal/src/Tests/d6/MigrateFileTest.php
index b38e8b5..6e383bc 100644
--- a/core/modules/migrate_drupal/src/Tests/d6/MigrateFileTest.php
+++ b/core/modules/migrate_drupal/src/Tests/d6/MigrateFileTest.php
@@ -10,16 +10,16 @@
 use Drupal\Component\Utility\Random;
 use Drupal\migrate\MigrateExecutable;
 use Drupal\migrate\Tests\MigrateDumpAlterInterface;
-use Drupal\migrate\Tests\MigrateTearDownInterface;
 use Drupal\migrate_drupal\Tests\d6\MigrateDrupal6TestBase;
 use Drupal\Core\Database\Database;
+use Drupal\simpletest\TestBase;
 
 /**
  * file migration.
  *
  * @group migrate_drupal
  */
-class MigrateFileTest extends MigrateDrupal6TestBase implements MigrateDumpAlterInterface, MigrateTearDownInterface {
+class MigrateFileTest extends MigrateDrupal6TestBase implements MigrateDumpAlterInterface {
 
   protected static $tempFilename;
 
@@ -34,9 +34,6 @@ class MigrateFileTest extends MigrateDrupal6TestBase implements MigrateDumpAlter
    * {@inheritdoc}
    */
   protected function setUp() {
-    // Set the temp file of the site to the same as the D6 site, this allows us
-    // to test files which start and finish in the same place.
-    $this->tempFilesDirectory = '/tmp';
     parent::setUp();
     $dumps = array(
       $this->getDumpDirectory() . '/Files.php',
@@ -53,13 +50,6 @@ protected function setUp() {
   }
 
   /**
-   * {@inheritdoc}
-   */
-  public static function migrateTearDown() {
-    unlink('/tmp/' . static::getUniqueFilename());
-  }
-
-  /**
    * Tests the Drupal 6 files to Drupal 8 migration.
    */
   public function testFiles() {
@@ -90,7 +80,7 @@ public function testFiles() {
       ->execute();
     Database::getConnection('default', 'migrate')
       ->update('variable')
-      ->fields(array('value' => serialize('/tmp')))
+      ->fields(array('value' => serialize($this->getTempFilesDirectory())))
       ->condition('name', 'file_directory_temp')
       ->execute();
     $executable = new MigrateExecutable($migration, $this);
@@ -113,28 +103,24 @@ public static function getUniqueFilename() {
   }
 
   /**
-   * Creates a random filename and updates the source database.
-   *
-   * @return string
-   *   A filename based upon the test.
-   *
-   * @see \Drupal\migrate_drupal\Tests\Dump\Files
+   * {@inheritdoc}
    */
-  public static function migrateDumpAlter($test_id) {
-    // If it is already set recreate the file and update again.
-    if (isset(static::$tempFilename)) {
-      unlink('/tmp/' . static::getUniqueFilename());
-    }
+  public static function migrateDumpAlter(TestBase $test) {
+    // Creates a random filename and updates the source database.
     $random = new Random();
-    static::$tempFilename = $test_id . $random->name() . '.jpg';
-    file_put_contents('/tmp/' . static::$tempFilename, '');
-    Database::getConnection('default', 'migrate')->update('files')
+    $temp_directory = $test->getTempFilesDirectory();
+    static::$tempFilename = $test->getDatabasePrefix() . $random->name() . '.jpg';
+    $file_path = $temp_directory . '/' . static::$tempFilename;
+    file_put_contents($file_path, '');
+    Database::getConnection('default', 'migrate')
+      ->update('files')
       ->condition('fid', 6)
       ->fields(array(
         'filename' => static::$tempFilename,
-        'filepath' => '/tmp/' . static::$tempFilename,
+        'filepath' => $file_path,
       ))
       ->execute();
+
     return static::$tempFilename;
   }
 
diff --git a/core/modules/simpletest/src/TestBase.php b/core/modules/simpletest/src/TestBase.php
index a95bade..9a38774 100644
--- a/core/modules/simpletest/src/TestBase.php
+++ b/core/modules/simpletest/src/TestBase.php
@@ -1652,4 +1652,24 @@ protected function config($name) {
     return \Drupal::configFactory()->getEditable($name);
   }
 
+  /**
+   * Gets the database prefix.
+   *
+   * @return string
+   *   The database prefix
+   */
+  public function getDatabasePrefix() {
+    return $this->databasePrefix;
+  }
+
+  /**
+   * Gets the temporary files directory.
+   *
+   * @return string
+   *   The temporary files directory.
+   */
+  public function getTempFilesDirectory() {
+    return $this->tempFilesDirectory;
+  }
+
 }