diff --git a/backend/app/api/calendar.py b/backend/app/api/calendar.py
index 6e9d355..cb66043 100644
--- a/backend/app/api/calendar.py
+++ b/backend/app/api/calendar.py
@@ -209,16 +209,25 @@ def list_events(cal_id):
     end = request.args.get('end')
 
     query = CalendarEvent.query.filter_by(calendar_id=cal_id)
+    # Wiederkehrende Termine duerfen nicht per Range gefiltert werden -
+    # die FullCalendar-RRULE-Plugin-Expansion im Frontend braucht den
+    # Master-Event auch wenn dessen dtstart vor dem sichtbaren Bereich liegt.
     if start:
         try:
             start_dt = datetime.fromisoformat(start)
-            query = query.filter(CalendarEvent.dtend >= start_dt)
+            query = query.filter(db.or_(
+                CalendarEvent.recurrence_rule.isnot(None),
+                CalendarEvent.dtend >= start_dt,
+            ))
         except ValueError:
             pass
     if end:
         try:
             end_dt = datetime.fromisoformat(end)
-            query = query.filter(CalendarEvent.dtstart <= end_dt)
+            query = query.filter(db.or_(
+                CalendarEvent.recurrence_rule.isnot(None),
+                CalendarEvent.dtstart <= end_dt,
+            ))
         except ValueError:
             pass