diff --git a/phpseclib/Crypt/RC4.php b/phpseclib/Crypt/RC4.php
index 4812010c..25e4ff85 100644
--- a/phpseclib/Crypt/RC4.php
+++ b/phpseclib/Crypt/RC4.php
@@ -107,7 +107,7 @@ class RC4 extends Base
      * @var string
      * @access private
      */
-    var $key = "\0";
+    var $key;
 
     /**
      * The Key Stream for decryption and encryption