diff --git a/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine b/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine
index a1da728..8907983 100644
--- a/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine
+++ b/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine
@@ -8,7 +8,10 @@
 use Drupal\Core\Extension\Extension;
 
 /**
- * Implements hook_init().
+ * Includes .theme file, which contains functions to support theming.
+ *
+ * @param \Drupal\Core\Extension\Extension $theme
+ *   Theme template object.
  */
 function nyan_cat_init(Extension $theme) {
   $theme->load();
diff --git a/core/themes/engines/twig/twig.engine b/core/themes/engines/twig/twig.engine
index 30ec511..778cb43 100644
--- a/core/themes/engines/twig/twig.engine
+++ b/core/themes/engines/twig/twig.engine
@@ -26,7 +26,10 @@ function twig_extension() {
 }
 
 /**
- * Implements hook_init().
+ * Includes .theme file, which contains functions to support theming.
+ *
+ * @param \Drupal\Core\Extension\Extension $theme
+ *   Theme template object.
  */
 function twig_init(Extension $theme) {
   $theme->load();