diff --git a/core/lib/Drupal/Component/Plugin/PluginBag.php b/core/lib/Drupal/Component/Plugin/PluginBag.php
index 9487d8c..54718be 100644
--- a/core/lib/Drupal/Component/Plugin/PluginBag.php
+++ b/core/lib/Drupal/Component/Plugin/PluginBag.php
@@ -86,6 +86,9 @@ public function set($instance_id, $value) {
    * Removes an initialized plugin.
    *
    * The plugin can still be used, it will be reinitialized.
+   *
+   * @param string $instance_id
+   *   The ID of the plugin instance to remove.
    */
   public function remove($instance_id) {
     unset($this->pluginInstances[$instance_id]);