diff --git a/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php b/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php
index 2d34d2c..cb55040 100644
--- a/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php
+++ b/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php
@@ -59,7 +59,7 @@ public function createInstance($plugin_id, array $configuration) {
   public static function getPluginClass($plugin_id, DiscoveryInterface $discovery) {
     $plugin_definition = $discovery->getDefinition($plugin_id);
     if (empty($plugin_definition)) {
-      throw new PluginException(sprintf('The plugin (%s) does not exist.', $plugin_id));
+      throw new PluginException(sprintf('The plugin (%s) does not exist (%s discovery).', $plugin_id, get_class($discovery)));
     }
     if (empty($plugin_definition['class'])) {
       throw new PluginException(sprintf('The plugin (%s) did not specify a class in its definition.', $plugin_id));