diff --git a/django-stubs/contrib/admin/options.pyi b/django-stubs/contrib/admin/options.pyi
index 5b2146c..bfa2351 100644
--- a/django-stubs/contrib/admin/options.pyi
+++ b/django-stubs/contrib/admin/options.pyi
@@ -61,10 +61,10 @@ class BaseModelAdmin:
     def formfield_for_choice_field(self, db_field: Field, request: WSGIRequest, **kwargs: Any) -> TypedChoiceField: ...
     def get_field_queryset(self, db: None, db_field: RelatedField, request: WSGIRequest) -> Optional[QuerySet]: ...
     def formfield_for_foreignkey(
-        self, db_field: ForeignKey, request: WSGIRequest, **kwargs: Any
+        self, db_field: ForeignKey, request: Optional[WSGIRequest], **kwargs: Any
     ) -> Optional[ModelChoiceField]: ...
     def formfield_for_manytomany(
-        self, db_field: ManyToManyField, request: WSGIRequest, **kwargs: Any
+        self, db_field: ManyToManyField, request: Optional[WSGIRequest], **kwargs: Any
     ) -> ModelMultipleChoiceField: ...
     def get_autocomplete_fields(self, request: WSGIRequest) -> Tuple: ...
     def get_view_on_site_url(self, obj: Optional[Model] = ...) -> Optional[str]: ...
diff --git a/django-stubs/contrib/admin/utils.pyi b/django-stubs/contrib/admin/utils.pyi
index 7fd9db9..cc54957 100644
--- a/django-stubs/contrib/admin/utils.pyi
+++ b/django-stubs/contrib/admin/utils.pyi
@@ -43,7 +43,7 @@ class NestedObjects(Collector):
     def add_edge(self, source: Optional[Model], target: Model) -> None: ...
     def collect(
         self,
-        objs: Union[Sequence[Model], QuerySet],
+        objs: Union[Sequence[Optional[Model]], QuerySet],
         source: Optional[Type[Model]] = ...,
         source_attr: Optional[str] = ...,
         **kwargs: Any
diff --git a/django-stubs/contrib/auth/admin.pyi b/django-stubs/contrib/auth/admin.pyi
index 2d77835..2c541eb 100644
--- a/django-stubs/contrib/auth/admin.pyi
+++ b/django-stubs/contrib/auth/admin.pyi
@@ -1,9 +1,13 @@
-from typing import Any, Dict, List, Optional, Tuple, Type
+from typing import Any, Dict, List, Optional, Tuple, Type, Union
 
 from django.contrib.auth.models import User, Group
 from django.core.handlers.wsgi import WSGIRequest
+from django.db.models.fields import Field
 from django.db.models.fields.related import ManyToManyField
+from django.db.models.options import Options
 from django.forms.models import ModelMultipleChoiceField
+from django.forms.fields import Field as FormField
+from django.forms.widgets import Widget
 from django.http.response import HttpResponse
 from django.urls.resolvers import URLPattern
 
@@ -27,10 +31,7 @@ class GroupAdmin(admin.ModelAdmin):
 
 class UserAdmin(admin.ModelAdmin):
     admin_site: AdminSite
-    formfield_overrides: Dict[
-        Type[Union[django.db.models.fields.DateTimeCheckMixin, Field]],
-        Dict[str, Type[Union[django.forms.fields.SplitDateTimeField, Widget]]],
-    ]
+    formfield_overrides: Dict[Type[Field], Dict[str, Type[Union[FormField, Widget]]]]
     model: Type[User]
     opts: Options
     add_form_template: str = ...
diff --git a/django-stubs/db/migrations/operations/models.pyi b/django-stubs/db/migrations/operations/models.pyi
index 2676046..7c1a3d5 100644
--- a/django-stubs/db/migrations/operations/models.pyi
+++ b/django-stubs/db/migrations/operations/models.pyi
@@ -46,12 +46,12 @@ class FieldRelatedOptionOperation(ModelOptionOperation): ...
 class AlterUniqueTogether(FieldRelatedOptionOperation):
     option_name: str = ...
     unique_together: Collection[Sequence[str]] = ...
-    def __init__(self, name: str, unique_together: Collection[Sequence[str]]) -> None: ...
+    def __init__(self, name: str, unique_together: Optional[Collection[Sequence[str]]]) -> None: ...
 
 class AlterIndexTogether(FieldRelatedOptionOperation):
     option_name: str = ...
     index_together: Collection[Sequence[str]] = ...
-    def __init__(self, name: str, index_together: Collection[Sequence[str]]) -> None: ...
+    def __init__(self, name: str, index_together: Optional[Collection[Sequence[str]]]) -> None: ...
 
 class AlterOrderWithRespectTo(FieldRelatedOptionOperation):
     order_with_respect_to: str = ...
diff --git a/django-stubs/http/response.pyi b/django-stubs/http/response.pyi
index 04b6e6f..e50943e 100644
--- a/django-stubs/http/response.pyi
+++ b/django-stubs/http/response.pyi
@@ -33,7 +33,7 @@ class HttpResponseBase(Iterable[AnyStr]):
     def has_header(self, header: str) -> bool: ...
     def items(self) -> Iterable[Tuple[str, str]]: ...
     @overload
-    def get(self, header: Union[str, bytes], alternate: str) -> str: ...
+    def get(self, header: Union[str, bytes], alternate: Optional[str]) -> str: ...
     @overload
     def get(self, header: Union[str, bytes]) -> Optional[str]: ...
     def set_cookie(