diff --git a/system/libraries/Session/drivers/Session_memcached_driver.php b/system/libraries/Session/drivers/Session_memcached_driver.php
index 600b8ca..f1a6e24 100644
--- a/system/libraries/Session/drivers/Session_memcached_driver.php
+++ b/system/libraries/Session/drivers/Session_memcached_driver.php
@@ -361,7 +361,7 @@
 		{
 			if ( ! $this->_memcached->delete($this->_lock_key) && $this->_memcached->getResultCode() !== Memcached::RES_NOTFOUND)
 			{
-				log_message('error', 'Session: Error while trying to free lock for '.$this->_key_prefix.$session_id);
+				log_message('error', 'Session: Error while trying to free lock for '.$this->_lock_key);
 				return FALSE;
 			}
 
diff --git a/system/libraries/Session/drivers/Session_redis_driver.php b/system/libraries/Session/drivers/Session_redis_driver.php
index c3c75b3..1cc4d75 100644
--- a/system/libraries/Session/drivers/Session_redis_driver.php
+++ b/system/libraries/Session/drivers/Session_redis_driver.php
@@ -381,7 +381,7 @@
 		{
 			if ( ! $this->_redis->delete($this->_lock_key))
 			{
-				log_message('error', 'Session: Error while trying to free lock for '.$this->_key_prefix.$session_id);
+				log_message('error', 'Session: Error while trying to free lock for '.$this->_lock_key);
 				return FALSE;
 			}