diff --git a/core/lib/Drupal/Core/Extension/InfoParserInterface.php b/core/lib/Drupal/Core/Extension/InfoParserInterface.php
index 2c6e2d1..17abfc7 100644
--- a/core/lib/Drupal/Core/Extension/InfoParserInterface.php
+++ b/core/lib/Drupal/Core/Extension/InfoParserInterface.php
@@ -36,6 +36,7 @@
    * - screenshot: Path to screenshot relative to the theme's .info.yml file.
    * - engine: Theme engine; typically twig.
    * - base theme: Name of a base theme, if applicable.
+   * - hidden: Sets the theme to not display in the administrative interface.
    * - regions: Listed regions.
    * - features: Features available.
    * - stylesheets: Theme stylesheets.