diff --git a/lib/mathslib.php b/lib/mathslib.php
index 6cee99a3e32e2..7603237ed62a5 100644
--- a/lib/mathslib.php
+++ b/lib/mathslib.php
@@ -35,7 +35,7 @@
  * @copyright Petr Skoda (skodak)
   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class calc_formula {
+class calc_formula { // Test
 
     // private properties
     var $_em;