diff --git a/public/mod/forum/lib.php b/public/mod/forum/lib.php
index d93cc3a8e24..17c17d33fde 100644
--- a/public/mod/forum/lib.php
+++ b/public/mod/forum/lib.php
@@ -5006,7 +5006,7 @@ function forum_reset_gradebook($courseid, $type='') {
  *
  * @global object
  * @global object
- * @param $data the data submitted from the reset course.
+ * @param stdClass $data the data submitted from the reset course.
  * @return array status array
  */
 function forum_reset_userdata($data) {
@@ -5209,7 +5209,13 @@ function forum_reset_userdata($data) {
     if ($data->timeshift) {
         // Any changes to the list of dates that needs to be rolled should be same during course restore and course reset.
         // See MDL-9367.
-        shift_course_mod_dates('forum', ['assesstimestart', 'assesstimefinish'], $data->timeshift, $data->courseid);
+        shift_course_mod_dates('forum', [
+            'assesstimestart',
+            'assesstimefinish',
+            'duedate',
+            'cutoffdate',
+        ], $data->timeshift, $data->courseid);
+
         $status[] = [
             'component' => $componentstr,
             'item' => get_string('date'),
diff --git a/public/mod/forum/tests/lib_test.php b/public/mod/forum/tests/lib_test.php
index a82bd69ef01..87e18a94043 100644
--- a/public/mod/forum/tests/lib_test.php
+++ b/public/mod/forum/tests/lib_test.php
@@ -4285,4 +4285,34 @@ final class lib_test extends \advanced_testcase {
         $f3discussionscount = forum_count_discussions($forum3, $forum3cm, $course2);
         $this->assertEquals(0, $f3discussionscount);
     }
+
+    /**
+     * @covers ::forum_reset_userdata
+     */
+    public function test_forum_reset_userdata(): void {
+        global $DB;
+
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        $now = time();
+
+        $course = $this->getDataGenerator()->create_course();
+        $forum = $this->getDataGenerator()->create_module('forum', [
+            'course' => $course->id,
+            'duedate' => $now + HOURSECS,
+            'cutoffdate' => $now + DAYSECS,
+        ]);
+
+        forum_reset_userdata((object) [
+            'courseid' => $course->id,
+            'timeshift' => DAYSECS * 2,
+        ]);
+
+        // Reload the instance data.
+        $instance = $DB->get_record('forum', ['id' => $forum->id]);
+
+        $this->assertEquals($forum->duedate + (DAYSECS * 2), $instance->duedate);
+        $this->assertEquals($forum->cutoffdate + (DAYSECS * 2), $instance->cutoffdate);
+    }
 }