3 files changed, 7 insertions, 4 deletions
diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index 0c58e7749c..6c11830d9c 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -12,7 +12,7 @@ from django.core.exceptions import EmptyResultSet, FieldError, FullResultSet
 from django.db import DatabaseError, NotSupportedError, connection
 from django.db.models import fields
 from django.db.models.constants import LOOKUP_SEP
-from django.db.models.query_utils import Q
+from django.db.models.query_utils import PROHIBITED_FILTER_KWARGS, Q
 from django.utils.deconstruct import deconstructible
 from django.utils.functional import cached_property, classproperty
 from django.utils.hashable import make_hashable
@@ -1640,6 +1640,9 @@ class When(Expression):
 
     def __init__(self, condition=None, then=None, **lookups):
         if lookups:
+            if invalid_kwargs := PROHIBITED_FILTER_KWARGS.intersection(lookups):
+                invalid_str = ", ".join(f"'{k}'" for k in sorted(invalid_kwargs))
+                raise TypeError(f"The following kwargs are invalid: {invalid_str}")
             if condition is None:
                 condition, lookups = Q(**lookups), None
             elif getattr(condition, "conditional", False):
diff --git a/django/db/models/query.py b/django/db/models/query.py
index dca504e441..43b55a76d0 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -29,7 +29,7 @@ from django.db.models.deletion import Collector
 from django.db.models.expressions import Case, DatabaseDefault, F, OrderBy, Value, When
 from django.db.models.fetch_modes import FETCH_ONE
 from django.db.models.functions import Cast, Trunc
-from django.db.models.query_utils import FilteredRelation, Q
+from django.db.models.query_utils import PROHIBITED_FILTER_KWARGS, FilteredRelation, Q
 from django.db.models.sql.constants import GET_ITERATOR_CHUNK_SIZE, ROW_COUNT
 from django.db.models.utils import (
     AltersData,
@@ -46,8 +46,6 @@ MAX_GET_RESULTS = 21
 # The maximum number of items to display in a QuerySet.__repr__
 REPR_OUTPUT_SIZE = 20
 
-PROHIBITED_FILTER_KWARGS = frozenset(["_connector", "_negated"])
-
 
 class BaseIterable:
     def __init__(
diff --git a/django/db/models/query_utils.py b/django/db/models/query_utils.py
index 8920977cd2..a17274fba0 100644
--- a/django/db/models/query_utils.py
+++ b/django/db/models/query_utils.py
@@ -21,6 +21,8 @@ from django.utils.hashable import make_hashable
 
 logger = logging.getLogger("django.db.models")
 
+PROHIBITED_FILTER_KWARGS = frozenset(["_connector", "_negated"])
+
 # PathInfo is used when converting lookups (fk__somecol). The contents
 # describe the relation in Model terms (model Options and Fields for both
 # sides of the relation. The join_field is the field backing the relation.