diff --git a/src/Mustache/Engine.php b/src/Mustache/Engine.php
index c9bc847..9eb03d1 100644
--- a/src/Mustache/Engine.php
+++ b/src/Mustache/Engine.php
@@ -45,6 +45,11 @@ class Mustache_Engine
     private $logger;
     private $strictCallables = false;
 
+    // Services
+    private $tokenizer;
+    private $parser;
+    private $compiler;
+
     /**
      * Mustache class constructor.
      *
diff --git a/src/Mustache/Loader/ArrayLoader.php b/src/Mustache/Loader/ArrayLoader.php
index 1667bfd..e7ece91 100644
--- a/src/Mustache/Loader/ArrayLoader.php
+++ b/src/Mustache/Loader/ArrayLoader.php
@@ -26,6 +26,7 @@
  */
 class Mustache_Loader_ArrayLoader implements Mustache_Loader, Mustache_Loader_MutableLoader
 {
+    private $templates;
 
     /**
      * ArrayLoader constructor.
diff --git a/src/Mustache/Logger/StreamLogger.php b/src/Mustache/Logger/StreamLogger.php
index aa47319..d422340 100644
--- a/src/Mustache/Logger/StreamLogger.php
+++ b/src/Mustache/Logger/StreamLogger.php
@@ -31,6 +31,7 @@ class Mustache_Logger_StreamLogger extends Mustache_Logger_AbstractLogger
         self::EMERGENCY => 600,
     );
 
+    protected $level;
     protected $stream = null;
     protected $url    = null;