diff --git a/course/format/lib.php b/course/format/lib.php
index edc7dbf9e47..35d371db0bc 100644
--- a/course/format/lib.php
+++ b/course/format/lib.php
@@ -96,6 +96,9 @@ abstract class format_base {
      * @return string
      */
     protected static final function get_format_or_default($format) {
+        global $CFG;
+        require_once($CFG->dirroot . '/course/lib.php');
+
         if (array_key_exists($format, self::$classesforformat)) {
             return self::$classesforformat[$format];
         }