diff --git a/app/lib/timetable/src/logic/timetable_builder.dart b/app/lib/timetable/src/logic/timetable_builder.dart
index 56af6c6fc..6e061564f 100644
--- a/app/lib/timetable/src/logic/timetable_builder.dart
+++ b/app/lib/timetable/src/logic/timetable_builder.dart
@@ -73,7 +73,7 @@ class TimetableBuilder {
       start: event.startTime,
       end: event.endTime,
       data: event,
-      groupInfo: groupInfo[event.groupID]!,
+      groupInfo: groupInfo[event.groupID],
       priority: 1,
       properties: properties,
     );