diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
index 102b1df..959e2ee 100644
--- a/system/libraries/Encrypt.php
+++ b/system/libraries/Encrypt.php
@@ -449,7 +449,7 @@
 	 */
 	protected function _get_cipher()
 	{
-		if ($this->_mcrypt_cipher === '')
+		if ($this->_mcrypt_cipher === NULL)
 		{
 			return $this->_mcrypt_cipher = MCRYPT_RIJNDAEL_256;
 		}
@@ -466,7 +466,7 @@
 	 */
 	protected function _get_mode()
 	{
-		if ($this->_mcrypt_mode === '')
+		if ($this->_mcrypt_mode === NULL)
 		{
 			return $this->_mcrypt_mode = MCRYPT_MODE_CBC;
 		}