diff --git a/Singleton/Singleton.php b/Singleton/Singleton.php
index ce7ee25a2..0aee908cd 100644
--- a/Singleton/Singleton.php
+++ b/Singleton/Singleton.php
@@ -10,7 +10,7 @@ class Singleton
     /**
      * @var cached reference to singleton instance 
      */
-    protected static $instance;
+    private static $instance;
     
     /**
      * gets the instance via lazy initialization (created on first usage)