diff --git a/core/tests/Drupal/Tests/TestFileCreationTrait.php b/core/tests/Drupal/Tests/TestFileCreationTrait.php
index 5bb5394..33d36fb 100644
--- a/core/tests/Drupal/Tests/TestFileCreationTrait.php
+++ b/core/tests/Drupal/Tests/TestFileCreationTrait.php
@@ -24,7 +24,7 @@
    * The first time this method is called, it will call
    * $this->generateFile() to generate binary and ASCII text files in the
    * public:// directory. It will also copy all files in
-   * core/modules/simpletest/files to public://. These contain image, SQL, PHP,
+   * core/tests/fixtures/files to public://. These contain image, SQL, PHP,
    * JavaScript, and HTML files.
    *
    * All filenames are prefixed with their type and have appropriate extensions:
@@ -67,8 +67,8 @@ protected function getTestFiles($type, $size = NULL) {
         $this->generateFile('text-' . $count++, 64, $line, 'text');
       }
 
-      // Copy other test files from simpletest.
-      $original = drupal_get_path('module', 'simpletest') . '/files';
+      // Copy other test files.
+      $original = \Drupal::root() . '/core/tests/fixtures/files';
       $files = file_scan_directory($original, '/(html|image|javascript|php|sql)-.*/');
       foreach ($files as $file) {
         file_unmanaged_copy($file->uri, PublicStream::basePath());
diff --git a/core/modules/simpletest/files/README.txt b/core/tests/fixtures/files/README.txt
similarity index 100%
rename from core/modules/simpletest/files/README.txt
rename to core/tests/fixtures/files/README.txt
diff --git a/core/modules/simpletest/files/html-1.txt b/core/tests/fixtures/files/html-1.txt
similarity index 100%
rename from core/modules/simpletest/files/html-1.txt
rename to core/tests/fixtures/files/html-1.txt
diff --git a/core/modules/simpletest/files/html-2.html b/core/tests/fixtures/files/html-2.html
similarity index 100%
rename from core/modules/simpletest/files/html-2.html
rename to core/tests/fixtures/files/html-2.html
diff --git a/core/modules/simpletest/files/image-1.png b/core/tests/fixtures/files/image-1.png
similarity index 100%
rename from core/modules/simpletest/files/image-1.png
rename to core/tests/fixtures/files/image-1.png
diff --git a/core/modules/simpletest/files/image-2.jpg b/core/tests/fixtures/files/image-2.jpg
similarity index 100%
rename from core/modules/simpletest/files/image-2.jpg
rename to core/tests/fixtures/files/image-2.jpg
diff --git a/core/modules/simpletest/files/image-test-no-transparency.gif b/core/tests/fixtures/files/image-test-no-transparency.gif
similarity index 100%
rename from core/modules/simpletest/files/image-test-no-transparency.gif
rename to core/tests/fixtures/files/image-test-no-transparency.gif
diff --git a/core/modules/simpletest/files/image-test-transparent-indexed.gif b/core/tests/fixtures/files/image-test-transparent-indexed.gif
similarity index 100%
rename from core/modules/simpletest/files/image-test-transparent-indexed.gif
rename to core/tests/fixtures/files/image-test-transparent-indexed.gif
diff --git a/core/modules/simpletest/files/image-test-transparent-out-of-range.gif b/core/tests/fixtures/files/image-test-transparent-out-of-range.gif
similarity index 100%
rename from core/modules/simpletest/files/image-test-transparent-out-of-range.gif
rename to core/tests/fixtures/files/image-test-transparent-out-of-range.gif
diff --git a/core/modules/simpletest/files/image-test.gif b/core/tests/fixtures/files/image-test.gif
similarity index 100%
rename from core/modules/simpletest/files/image-test.gif
rename to core/tests/fixtures/files/image-test.gif
diff --git a/core/modules/simpletest/files/image-test.jpg b/core/tests/fixtures/files/image-test.jpg
similarity index 100%
rename from core/modules/simpletest/files/image-test.jpg
rename to core/tests/fixtures/files/image-test.jpg
diff --git a/core/modules/simpletest/files/image-test.png b/core/tests/fixtures/files/image-test.png
similarity index 100%
rename from core/modules/simpletest/files/image-test.png
rename to core/tests/fixtures/files/image-test.png
diff --git a/core/modules/simpletest/files/javascript-1.txt b/core/tests/fixtures/files/javascript-1.txt
similarity index 100%
rename from core/modules/simpletest/files/javascript-1.txt
rename to core/tests/fixtures/files/javascript-1.txt
diff --git a/core/modules/simpletest/files/javascript-2.script b/core/tests/fixtures/files/javascript-2.script
similarity index 100%
rename from core/modules/simpletest/files/javascript-2.script
rename to core/tests/fixtures/files/javascript-2.script
diff --git a/core/modules/simpletest/files/php-1.txt b/core/tests/fixtures/files/php-1.txt
similarity index 100%
rename from core/modules/simpletest/files/php-1.txt
rename to core/tests/fixtures/files/php-1.txt
diff --git a/core/modules/simpletest/files/php-2.php b/core/tests/fixtures/files/php-2.php
similarity index 100%
rename from core/modules/simpletest/files/php-2.php
rename to core/tests/fixtures/files/php-2.php
diff --git a/core/modules/simpletest/files/sql-1.txt b/core/tests/fixtures/files/sql-1.txt
similarity index 100%
rename from core/modules/simpletest/files/sql-1.txt
rename to core/tests/fixtures/files/sql-1.txt
diff --git a/core/modules/simpletest/files/sql-2.sql b/core/tests/fixtures/files/sql-2.sql
similarity index 100%
rename from core/modules/simpletest/files/sql-2.sql
rename to core/tests/fixtures/files/sql-2.sql
diff --git a/core/modules/simpletest/files/translations/drupal-8.0.0-beta2.hu.po b/core/tests/fixtures/files/translations/drupal-8.0.0-beta2.hu.po
similarity index 100%
rename from core/modules/simpletest/files/translations/drupal-8.0.0-beta2.hu.po
rename to core/tests/fixtures/files/translations/drupal-8.0.0-beta2.hu.po
diff --git a/core/modules/simpletest/files/translations/drupal-8.0.0.de.po b/core/tests/fixtures/files/translations/drupal-8.0.0.de.po
similarity index 100%
rename from core/modules/simpletest/files/translations/drupal-8.0.0.de.po
rename to core/tests/fixtures/files/translations/drupal-8.0.0.de.po