diff --git a/core/lib/Drupal/Component/Plugin/Derivative/DeriverInterface.php b/core/lib/Drupal/Component/Plugin/Derivative/DeriverInterface.php
index 1133bce..e803fc8 100644
--- a/core/lib/Drupal/Component/Plugin/Derivative/DeriverInterface.php
+++ b/core/lib/Drupal/Component/Plugin/Derivative/DeriverInterface.php
@@ -30,8 +30,9 @@ public function getDerivativeDefinition($derivative_id, $base_plugin_definition)
   /**
    * Gets the definition of all derivatives of a base plugin.
    *
-   * @param array $base_plugin_definition
-   *   The definition array of the base plugin.
+   * @param mixed $base_plugin_definition
+   *   The definition of the base plugin. It is maybe an entire object or just
+   *   some array, depending on the discovery mechanism.
    * @return array
    *   An array of full derivative definitions keyed on derivative id.
    *