diff --git a/core/lib/Drupal/Core/Plugin/Discovery/YamlDiscoveryDecorator.php b/core/lib/Drupal/Core/Plugin/Discovery/YamlDiscoveryDecorator.php
index df973f5..eb63ea2 100644
--- a/core/lib/Drupal/Core/Plugin/Discovery/YamlDiscoveryDecorator.php
+++ b/core/lib/Drupal/Core/Plugin/Discovery/YamlDiscoveryDecorator.php
@@ -7,6 +7,9 @@
 
 namespace Drupal\Core\Plugin\Discovery;
 
+/**
+ * Enables YAML discovery for plugin definitions.
+ */
 class YamlDiscoveryDecorator extends YamlDiscovery {
 
   /**
@@ -17,7 +20,7 @@ class YamlDiscoveryDecorator extends YamlDiscovery {
   protected $decorated;
 
   /**
-   * Constructs a \Drupal\Component\Plugin\Discovery\StaticDiscoveryDecorator object.
+   * Constructs a YamlDiscoveryDecorator object.
    *
    * @param \Drupal\Component\Plugin\Discovery\DiscoveryInterface $decorated
    *   The discovery object that is being decorated.
@@ -37,11 +40,11 @@ public function __construct(DiscoveryInterface $decorated, $name, array $directo
    * {@inheritdoc}
    */
   public function getDefinitions() {
-    return $this->getDefinitions() + $this->decorated->getDefinitions();
+    return parent::getDefinitions() + $this->decorated->getDefinitions();
   }
 
   /**
-   * Passes through all unknown calls onto the decorated object
+   * Passes through all unknown calls onto the decorated object.
    */
   public function __call($method, $args) {
     return call_user_func_array(array($this->decorated, $method), $args);