diff --git a/AKModel/models.py b/AKModel/models.py
index 8e221a3af7a5227d2e8e664e25ad7487f2b8dab2..3f5a0f4ce26a787afff8bd0988d7000ac8ce8066 100644
--- a/AKModel/models.py
+++ b/AKModel/models.py
@@ -599,6 +599,9 @@ class Room(models.Model):
 
         data["fulfilled_room_constraints"].append(f"availability-room-{self.pk}")
 
+        if not any(constr.startswith("proxy") for constr in data["fulfilled_room_constraints"]):
+            data["fulfilled_room_constraints"].append("no-proxy")
+
         return json.dumps(data)
 
 
@@ -736,6 +739,9 @@ class AKSlot(models.Model):
         if self.room is not None:
             data["room_constraints"].append(f"availability-room-{self.room.pk}")
 
+        if not any(constr.startswith("proxy") for constr in data["room_constraints"]):
+            data["room_constraints"].append("no-proxy")
+
         return json.dumps(data)
 
 class AKOrgaMessage(models.Model):