diff --git a/AKModel/views/ak.py b/AKModel/views/ak.py
index caee99b4c04a116c124c887da7c521d4997904bf..5e642dd5d054513947bc075835e925a1349b0bd3 100644
--- a/AKModel/views/ak.py
+++ b/AKModel/views/ak.py
@@ -134,13 +134,19 @@ class AKJSONExportView(AdminViewMixin, FilterByEventSlugMixin, ListView):
                     time_constraints.append("resolution")
 
                 # add fulfilled time constraints for all AKs that cannot happen during full event
-                self._generate_time_constraints("ak", ak_availabilities, timeslot.avail)
+                time_constraints.extend(
+                    self._generate_time_constraints("ak", ak_availabilities, timeslot.avail)
+                )
 
                 # add fulfilled time constraints for all persons that are not available for full event
-                self._generate_time_constraints("person", person_availabilities, timeslot.avail)
+                time_constraints.extend(
+                    self._generate_time_constraints("person", person_availabilities, timeslot.avail)
+                )
 
                 # add fulfilled time constraints for all rooms that are not available for full event
-                self._generate_time_constraints("room", room_availabilities, timeslot.avail)
+                time_constraints.extend(
+                    self._generate_time_constraints("room", room_availabilities, timeslot.avail)
+                )
 
                 # add fulfilled time constraints for all AKSlots fixed to happen during timeslot
                 time_constraints.extend([