diff --git a/classes/external/view_videotime.php b/classes/external/view_videotime.php
index a113015b..eab24825 100644
--- a/classes/external/view_videotime.php
+++ b/classes/external/view_videotime.php
@@ -75,6 +75,8 @@ public static function view_videotime($cmid) {
         require_login($course, false, $cm);
         require_capability('mod/videotime:view', $context);
 
+        \core\session\manager::write_close();
+
         $moduleinstance = videotime_instance::instance_by_id($cm->instance);
 
         // Trigger course_module_viewed event and completion.