diff --git a/core/modules/system/src/Tests/File/ScanDirectoryTest.php b/core/modules/system/src/Tests/File/ScanDirectoryTest.php
index 4b067f0..ebb9bf4 100644
--- a/core/modules/system/src/Tests/File/ScanDirectoryTest.php
+++ b/core/modules/system/src/Tests/File/ScanDirectoryTest.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\system\Tests\File;
 
+use Drupal\Core\Site\Settings;
+
 /**
  * Tests the file_scan_directory() function.
  *
@@ -146,4 +148,17 @@ function testOptionMinDepth() {
     $files = file_scan_directory($this->path, '/^javascript-/', array('min_depth' => 1));
     $this->assertTrue(empty($files), 'Minimum-depth of 1 successfully excludes files from current directory.');
   }
+
+  /**
+   * Tests file_scan_directory() obeys 'file_scan_ignore_directories' setting.
+   */
+  function testIgnoreDirectories() {
+    $files = file_scan_directory('core/modules/system/tests/fixtures/IgnoreDirectories', '/\.txt$/');
+    $this->assertEqual(2, count($files), '2 text files found when not ignoring directories.');
+
+    $this->settingsSet('file_scan_ignore_directories', ['frontend_framework']);
+    $files = file_scan_directory('core/modules/system/tests/fixtures/IgnoreDirectories', '/\.txt$/');
+    $this->assertEqual(1, count($files), '1 text files found when ignoring directories called "frontend_framework".');
+  }
+
 }
diff --git a/core/modules/system/tests/fixtures/IgnoreDirectories/a.txt b/core/modules/system/tests/fixtures/IgnoreDirectories/a.txt
new file mode 100644
index 0000000..e69de29
diff --git a/core/modules/system/tests/fixtures/IgnoreDirectories/frontend_framework/b.txt b/core/modules/system/tests/fixtures/IgnoreDirectories/frontend_framework/b.txt
new file mode 100644
index 0000000..e69de29