diff --git a/gregui/api/views/invitation.py b/gregui/api/views/invitation.py
index af633e83e82470f5e0faffd8dda283319fec4a22..2a36d024a488fcec3e01ec1d115bb9fd408143f3 100644
--- a/gregui/api/views/invitation.py
+++ b/gregui/api/views/invitation.py
@@ -288,8 +288,7 @@ class InvitedGuestView(GenericAPIView):
 
     @staticmethod
     def _illegal_fields(request_data, changeable_fields) -> List[str]:
-        # Check how many of the allowed fields are filled in
-        person_data = request_data["person"]
+        person_data = request_data.get("person", {})
         changed_fields = person_data.keys()
         return list(set(changed_fields) - set(changeable_fields))
 
diff --git a/gregui/tests/api/views/test_invitation.py b/gregui/tests/api/views/test_invitation.py
index 5883fea7c4ef326cb93e586e7b14a369a0d02bda..fba3f5d01a1053b7c0e532e809bac9b07b43bddb 100644
--- a/gregui/tests/api/views/test_invitation.py
+++ b/gregui/tests/api/views/test_invitation.py
@@ -433,7 +433,6 @@ def test_invalid_date_of_birth_rejected(client, invited_person_verified_nin):
 
     person = Person.objects.get()
     assert person.date_of_birth is None
-    response = client.post(url, data, format="json")
 
 
 @pytest.mark.django_db