diff --git a/composer.json b/composer.json
index c3173b7..a7cdc86 100644
--- a/composer.json
+++ b/composer.json
@@ -13,6 +13,7 @@
         "cweagans/composer-patches": "^1.0",
         "drupal-composer/drupal-scaffold": "^2.0.0",
         "drupal/claro": "^1.0@alpha",
+        "drupal/classitup": "1.x-dev",
         "drupal/config_actions": "1.x-dev",
         "drupal/convert_bundles": "^1.0@alpha",
         "drupal/cshs": "^1.0@beta",