fix #5545
diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index 9e81168..b464439 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -303,7 +303,7 @@
 	 * @param	string	$id
 	 * @return	bool
 	 */
-	public function validateId($id)
+	public function validateSessionId($id)
 	{
 		$this->_memcached->get($this->_key_prefix.$id);
 		return ($this->_memcached->getResultCode() === Memcached::RES_SUCCESS);