diff --git a/calendar/externallib.php b/calendar/externallib.php
index ea419c98a2d..8cfb4541628 100644
--- a/calendar/externallib.php
+++ b/calendar/externallib.php
@@ -915,10 +915,10 @@ class core_calendar_external extends external_api {
         $formoptions['eventtypes'] = $allowedeeventtypes;
         if ($courseid) {
             require_once($CFG->libdir . '/grouplib.php');
-            $groupcoursedata = groups_get_course_data($courseid);
-            if (!empty($groupcoursedata->groups)) {
+            $groupcoursedata = groups_get_all_groups($courseid);
+            if (!empty($groupcoursedata)) {
                 $formoptions['groups'] = [];
-                foreach ($groupcoursedata->groups as $groupid => $groupdata) {
+                foreach ($groupcoursedata as $groupid => $groupdata) {
                     $formoptions['groups'][$groupid] = $groupdata->name;
                 }
             }
diff --git a/calendar/lib.php b/calendar/lib.php
index 438be90ab8f..fb60ec92e43 100644
--- a/calendar/lib.php
+++ b/calendar/lib.php
@@ -3639,9 +3639,9 @@ function calendar_output_fragment_event_form($args) {
 
     if (is_null($eventid)) {
         if (!empty($courseid)) {
-            $groupcoursedata = groups_get_course_data($courseid);
+            $groupcoursedata = groups_get_all_groups($courseid);
             $formoptions['groups'] = [];
-            foreach ($groupcoursedata->groups as $groupid => $groupdata) {
+            foreach ($groupcoursedata as $groupid => $groupdata) {
                 $formoptions['groups'][$groupid] = format_string($groupdata->name, false, ['context' => $context]);
             }
         }
@@ -3683,9 +3683,9 @@ function calendar_output_fragment_event_form($args) {
         $formoptions['event'] = $event;
 
         if (!empty($event->courseid)) {
-            $groupcoursedata = groups_get_course_data($event->courseid);
+            $groupcoursedata = groups_get_all_groups($event->courseid);
             $formoptions['groups'] = [];
-            foreach ($groupcoursedata->groups as $groupid => $groupdata) {
+            foreach ($groupcoursedata as $groupid => $groupdata) {
                 $formoptions['groups'][$groupid] = format_string($groupdata->name, false, ['context' => $context]);
             }
         }