diff --git a/calendar/export.php b/calendar/export.php
index 8c5d175be65..04e6cf39a1c 100644
--- a/calendar/export.php
+++ b/calendar/export.php
@@ -77,7 +77,8 @@ if (!empty($day) && !empty($mon) && !empty($year)) {
 }
 
 if ($courseid != SITEID && !empty($courseid)) {
-    $course = $DB->get_record('course', array('id' => $courseid));
+    // Course ID must be valid and existing.
+    $course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
     $courses = array($course->id => $course);
     $issite = false;
 } else {
@@ -85,7 +86,7 @@ if ($courseid != SITEID && !empty($courseid)) {
     $courses = calendar_get_default_courses();
     $issite = true;
 }
-require_course_login($course);
+require_login($course, false);
 
 $url = new moodle_url('/calendar/export.php', array('time' => $time));
 
diff --git a/calendar/managesubscriptions.php b/calendar/managesubscriptions.php
index 3e4e0e98f69..f1c74d67238 100644
--- a/calendar/managesubscriptions.php
+++ b/calendar/managesubscriptions.php
@@ -45,13 +45,15 @@ $PAGE->set_pagelayout('admin');
 $PAGE->navbar->add(get_string('managesubscriptions', 'calendar'));
 
 if ($courseid != SITEID && !empty($courseid)) {
-    $course = $DB->get_record('course', array('id' => $courseid));
+    // Course ID must be valid and existing.
+    $course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
     $courses = array($course->id => $course);
 } else {
     $course = get_site();
     $courses = calendar_get_default_courses();
 }
-require_course_login($course);
+require_login($course, false);
+
 if (!calendar_user_can_add_event($course)) {
     print_error('errorcannotimport', 'calendar');
 }
diff --git a/calendar/view.php b/calendar/view.php
index a55aee6e195..18245a50e38 100644
--- a/calendar/view.php
+++ b/calendar/view.php
@@ -85,7 +85,8 @@ $url->param('time', $time);
 $PAGE->set_url($url);
 
 if ($courseid != SITEID && !empty($courseid)) {
-    $course = $DB->get_record('course', array('id' => $courseid));
+    // Course ID must be valid and existing.
+    $course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
     $courses = array($course->id => $course);
     $issite = false;
     navigation_node::override_active_url(new moodle_url('/course/view.php', array('id' => $course->id)));
@@ -95,7 +96,7 @@ if ($courseid != SITEID && !empty($courseid)) {
     $issite = true;
 }
 
-require_course_login($course);
+require_login($course, false);
 
 $calendar = new calendar_information(0, 0, 0, $time);
 $calendar->prepare_for_view($course, $courses);