diff --git a/core/tests/Drupal/Tests/Core/Asset/CssOptimizerUnitTest.php b/core/tests/Drupal/Tests/Core/Asset/CssOptimizerUnitTest.php
index f37d716..129adf5 100644
--- a/core/tests/Drupal/Tests/Core/Asset/CssOptimizerUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Asset/CssOptimizerUnitTest.php
@@ -170,8 +170,8 @@ function testOptimizeProvider() {
         ),
         '#home body { position: fixed; }',
       ),
-      // Subfolder file. Tests:
-      // - CSS import path is properly interpreted.
+      // File in subfolder. Tests:
+      // - CSS import path is properly interpreted. (https://drupal.org/node/1198904)
       5 => array(
         array(
           'group' => -100,