diff --git a/aleksis/apps/chronos/frontend/components/calendar_feeds/details/LessonDetails.vue b/aleksis/apps/chronos/frontend/components/calendar_feeds/details/LessonDetails.vue
index 2453c3e9e066d55b4c297022a38659e85f7ef65e..226d712333b13fc7519b4c3eb19383dd4dc5f0d1 100644
--- a/aleksis/apps/chronos/frontend/components/calendar_feeds/details/LessonDetails.vue
+++ b/aleksis/apps/chronos/frontend/components/calendar_feeds/details/LessonDetails.vue
@@ -252,9 +252,9 @@ export default {
     initPatchData() {
       return {
         id: this.selectedEvent.meta.id,
-        subject: this.selectedEvent.meta.subject,
-        teachers: this.selectedEvent.meta.teachers,
-        rooms: this.selectedEvent.meta.rooms,
+        subject: this.selectedEvent.meta.subject?.id,
+        teachers: this.selectedEvent.meta.teachers.map((teacher) => teacher.id),
+        rooms: this.selectedEvent.meta.rooms.map((room) => room.id),
         cancelled: this.selectedEvent.meta.cancelled,
         comment: this.selectedEvent.meta.comment,
       };