diff --git a/src/LanguageServer.php b/src/LanguageServer.php
index b4b2151..595c20b 100644
--- a/src/LanguageServer.php
+++ b/src/LanguageServer.php
@@ -76,6 +76,11 @@ class LanguageServer extends AdvancedJsonRpc\Dispatcher
      */
     protected $contentRetriever;
 
+    /**
+     * @var PhpDocumentLoader
+     */
+    protected $documentLoader;
+
     /**
      * @param PotocolReader  $reader
      * @param ProtocolWriter $writer