diff --git a/phpBB/includes/class_loader.php b/phpBB/includes/class_loader.php
index 2db807eb77..bc268d342e 100644
--- a/phpBB/includes/class_loader.php
+++ b/phpBB/includes/class_loader.php
@@ -38,6 +38,8 @@ class phpbb_class_loader
 
 	/**
 	* A map of looked up class names to paths relative to $this->path.
+	* This map is stored in cache and looked up if the cache is available.
+	*
 	* @var array
 	*/
 	private $cached_paths = array();