diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index 875e722..4bd6399 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -246,7 +246,7 @@
 	{
 		if (isset($this->_memcached))
 		{
-			isset($this->_lock_key) && $this->_memcached->delete($this->_lock_key);
+			$this->_release_lock();
 			if ( ! $this->_memcached->quit())
 			{
 				return $this->_failure;