diff --git a/calendar/lib.php b/calendar/lib.php
index 02f541bbb79..c51ba4c0239 100644
--- a/calendar/lib.php
+++ b/calendar/lib.php
@@ -2692,13 +2692,13 @@ function calendar_get_eventtype_choices($courseid) {
     calendar_get_allowed_types($allowed, $courseid);
 
     if ($allowed->user) {
-        $choices[0] = get_string('userevents', 'calendar');
+        $choices['user'] = get_string('userevents', 'calendar');
     }
     if ($allowed->site) {
-        $choices[SITEID] = get_string('globalevents', 'calendar');
+        $choices['site'] = get_string('globalevents', 'calendar');
     }
     if (!empty($allowed->courses)) {
-        $choices[$courseid] = get_string('courseevents', 'calendar');
+        $choices['course'] = get_string('courseevents', 'calendar');
     }
     if (!empty($allowed->groups) and is_array($allowed->groups)) {
         $choices['group'] = get_string('group');
@@ -2714,11 +2714,15 @@ function calendar_get_eventtype_choices($courseid) {
  * @return int The insert ID, if any.
  */
 function calendar_add_subscription($sub) {
-    global $DB, $USER;
+    global $DB, $USER, $SITE;
 
-    $sub->courseid = $sub->eventtype;
-    if ($sub->eventtype == 'group') {
+    if ($sub->eventtype === 'site') {
+        $sub->courseid = $SITE->id;
+    } else if ($sub->eventtype === 'group' || $sub->eventtype === 'course') {
         $sub->courseid = $sub->course;
+    } else {
+        // User events.
+        $sub->courseid = 0;
     }
     $sub->userid = $USER->id;
 
@@ -2794,10 +2798,10 @@ function calendar_add_icalendar_event($event, $courseid, $subscriptionid = null)
         $eventrecord->userid = $sub->userid;
         $eventrecord->groupid = $sub->groupid;
         $eventrecord->courseid = $sub->courseid;
+        $eventrecord->eventtype = $sub->eventtype;
     } else {
-        $eventrecord->userid = $USER->id;
-        $eventrecord->groupid = 0; // TODO: ???
-        $eventrecord->courseid = $courseid;
+        // We should never do anything with an event without a subscription reference.
+        return 0;
     }
 
     if ($updaterecord = $DB->get_record('event', array('uuid' => $eventrecord->uuid))) {
diff --git a/calendar/managesubscriptions_form.php b/calendar/managesubscriptions_form.php
index fcd7979c0b8..80ab634f9cc 100644
--- a/calendar/managesubscriptions_form.php
+++ b/calendar/managesubscriptions_form.php
@@ -74,11 +74,10 @@ class calendar_addsubscription_form extends moodleform {
         $mform->addHelpButton('pollinterval', 'pollinterval', 'calendar');
         $mform->setType('pollinterval', PARAM_INT);
 
-        // Eventtype: 0 = user, 1 = global, anything else = course ID.
         list($choices, $groups) = calendar_get_eventtype_choices($courseid);
         $mform->addElement('select', 'eventtype', get_string('eventkind', 'calendar'), $choices);
         $mform->addRule('eventtype', get_string('required'), 'required');
-        $mform->setType('eventtype', PARAM_INT);
+        $mform->setType('eventtype', PARAM_ALPHA);
 
         if (!empty($groups) and is_array($groups)) {
             $groupoptions = array();