diff --git a/backend/magic_plan/tests/test_magic_plan_trigger_request.py b/backend/magic_plan/tests/test_magic_plan_trigger_request.py
index 46a20a37..131ea93b 100644
--- a/backend/magic_plan/tests/test_magic_plan_trigger_request.py
+++ b/backend/magic_plan/tests/test_magic_plan_trigger_request.py
@@ -38,3 +38,11 @@ def test_extra_fields_ignored() -> None:
     req = MagicPlanTriggerRequest.model_validate(payload)
     # Assert
     assert req.address == "123 High St London SW1A 1AA"
+
+
+def test_missing_hubspot_deal_id_raises() -> None:
+    # Arrange
+    payload = {"address": "123 High St London SW1A 1AA"}
+    # Act / Assert
+    with pytest.raises(ValidationError):
+        MagicPlanTriggerRequest.model_validate(payload)