diff --git a/phpseclib/Crypt/Common/SymmetricKey.php b/phpseclib/Crypt/Common/SymmetricKey.php
index 5e3bd08b..0567cf6d 100644
--- a/phpseclib/Crypt/Common/SymmetricKey.php
+++ b/phpseclib/Crypt/Common/SymmetricKey.php
@@ -452,23 +452,11 @@ abstract class SymmetricKey
      * @see self::encrypt()
      * @see self::decrypt()
      * @see self::setupInlineCrypt()
-     * @see self::$use_inline_crypt
      * @var Callback
      * @access private
      */
     protected $inline_crypt;
 
-    /**
-     * Holds whether performance-optimized $inline_crypt() can/should be used.
-     *
-     * @see self::encrypt()
-     * @see self::decrypt()
-     * @see self::inline_crypt
-     * @var mixed
-     * @access private
-     */
-    protected $use_inline_crypt;
-
     /**
      * If OpenSSL can be used in ECB but not in CTR we can emulate CTR
      *
diff --git a/phpseclib/Crypt/RC4.php b/phpseclib/Crypt/RC4.php
index 7318a74b..14aca451 100644
--- a/phpseclib/Crypt/RC4.php
+++ b/phpseclib/Crypt/RC4.php
@@ -93,15 +93,6 @@ class RC4 extends StreamCipher
      */
     protected $cipher_name_mcrypt = 'arcfour';
 
-    /**
-     * Holds whether performance-optimized $inline_crypt() can/should be used.
-     *
-     * @see \phpseclib\Crypt\Common\SymmetricKey::inline_crypt
-     * @var mixed
-     * @access private
-     */
-    protected $use_inline_crypt = false; // currently not available
-
     /**
      * The Key
      *