diff --git a/AKModel/models.py b/AKModel/models.py
index 7e98bef5c9c8e6d61432c354b0ceda8928547b38..d36c0344cd281f5f4149774d041b755ef9adc5d0 100644
--- a/AKModel/models.py
+++ b/AKModel/models.py
@@ -652,6 +652,9 @@ 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)
 
 
@@ -790,6 +793,9 @@ 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):