diff --git a/core/Loader.php b/core/Loader.php
index b6d24e2b7bb26818f44333ac1830cc2c0aa906de..9d9b026ff8ebdbd2d0c655fc6f1524784c10afdc 100644
--- a/core/Loader.php
+++ b/core/Loader.php
@@ -58,6 +58,10 @@ class Piwik_Loader
 			for($i = 0; $i < count(self::$dirs); $i++)
 			{
 				$path = PIWIK_INCLUDE_PATH . self::$dirs[$i] . $classPath . '.php';
+				if(strpos($path, '..'))
+				{
+					continue;
+				}
 				if(file_exists($path))
 				{
 					require_once $path; // prefixed by PIWIK_INCLUDE_PATH