diff --git a/lib/classes/task/calendar_cron_task.php b/lib/classes/task/calendar_cron_task.php
index f4c874140ba..0eec2bfd2d8 100644
--- a/lib/classes/task/calendar_cron_task.php
+++ b/lib/classes/task/calendar_cron_task.php
@@ -25,7 +25,7 @@ namespace core\task;
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir . '/cronlib.php');
+require_once($CFG->dirroot . '/calendar/lib.php');
 
 /**
  * Simple task to run the calendar cron.
diff --git a/lib/deprecatedlib.php b/lib/deprecatedlib.php
index 6be8c82667f..facc5f3eee1 100644
--- a/lib/deprecatedlib.php
+++ b/lib/deprecatedlib.php
@@ -6612,6 +6612,7 @@ function calendar_cron() {
 
     global $CFG, $DB;
 
+    require_once($CFG->dirroot . '/calendar/lib.php');
     // In order to execute this we need bennu.
     require_once($CFG->libdir.'/bennu/bennu.inc.php');
 
diff --git a/lib/tests/calendar_cron_task_test.php b/lib/tests/calendar_cron_task_test.php
index fa410b9ecf3..f17ab150ece 100644
--- a/lib/tests/calendar_cron_task_test.php
+++ b/lib/tests/calendar_cron_task_test.php
@@ -24,6 +24,9 @@
 
 defined('MOODLE_INTERNAL') || die();
 
+global $CFG;
+require_once($CFG->dirroot . '/calendar/lib.php');
+
 /**
  * Class containing unit tests for the calendar cron task.
  *