diff --git a/app/controllers/my_courses.php b/app/controllers/my_courses.php
index b6dcac413d4b341c264c07a2f745beb1ee430616..21943fe65cb9ad24e8afdc1d183e4889473b23d3 100644
--- a/app/controllers/my_courses.php
+++ b/app/controllers/my_courses.php
@@ -28,6 +28,9 @@ require_once 'lib/object.inc.php';
 
 class MyCoursesController extends AuthenticatedController
 {
+    /**
+     * @var Callable
+     */
     private $performance_timer = null;
 
     public function before_filter(&$action, &$args)
diff --git a/lib/classes/Metrics.php b/lib/classes/Metrics.php
index d4dfbcf7dd72cca593a7e8eca929bad62e154fb8..c3874d5d4a1ab0ffe2e7dbd7a535c805c3982c20 100644
--- a/lib/classes/Metrics.php
+++ b/lib/classes/Metrics.php
@@ -159,7 +159,7 @@ class Metrics {
      *
      * @endcode
      *
-     * @return function  the timing function
+     * @return Callable  the timing function
      */
     public static function startTimer()
     {