Fix issue #904
diff --git a/system/core/Common.php b/system/core/Common.php
index 1f59c02..2f9c4ff 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -199,7 +199,7 @@
 */
 if ( ! function_exists('is_loaded'))
 {
-	function is_loaded($class = '')
+	function &is_loaded($class = '')
 	{
 		static $_is_loaded = array();