diff --git a/core/lib/Drupal/Core/Form/FormValidatorInterface.php b/core/lib/Drupal/Core/Form/FormValidatorInterface.php
index bf7632bd4fc19ad66bd3fb055f3c10806f7aa73e..13def56d729aa0d2497d78031bd421da33c7bd22 100644
--- a/core/lib/Drupal/Core/Form/FormValidatorInterface.php
+++ b/core/lib/Drupal/Core/Form/FormValidatorInterface.php
@@ -25,7 +25,7 @@ public function executeValidateHandlers(&$form, FormStateInterface &$form_state)
   /**
    * Validates user-submitted form data in the $form_state.
    *
-   * @param array $form_id
+   * @param string $form_id
    *   A unique string identifying the form for validation, submission,
    *   theming, and hook_form_alter functions.
    * @param array $form