diff --git a/strawberry_django/integrations/guardian.py b/strawberry_django/integrations/guardian.py
index d252f4065..f15baf444 100644
--- a/strawberry_django/integrations/guardian.py
+++ b/strawberry_django/integrations/guardian.py
@@ -1,7 +1,7 @@
 import contextlib
 import dataclasses
 import weakref
-from typing import Optional, Union, cast
+from typing import Optional, Type, Union, cast
 
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
@@ -24,7 +24,9 @@ class ObjectPermissionModels:
     group: GroupObjectPermissionBase
 
 
-def get_object_permission_models(model: models.Model):
+def get_object_permission_models(
+    model: Union[models.Model, Type[models.Model]],
+) -> ObjectPermissionModels:
     return ObjectPermissionModels(
         user=cast(UserObjectPermissionBase, get_user_obj_perms_model(model)),
         group=cast(GroupObjectPermissionBase, get_group_obj_perms_model(model)),
diff --git a/strawberry_django/mutations/resolvers.py b/strawberry_django/mutations/resolvers.py
index 9c1bfe795..fd13a1f9b 100644
--- a/strawberry_django/mutations/resolvers.py
+++ b/strawberry_django/mutations/resolvers.py
@@ -262,7 +262,10 @@ def prepare_create_update(
             (ParsedObject, str),
         ):
             value, value_data = _parse_data(  # noqa: PLW2901
-                info, field.related_model, value, key_attr=key_attr
+                info,
+                cast(type[Model], field.related_model),
+                value,
+                key_attr=key_attr,
             )
             if value is None and not value_data:
                 value = None  # noqa: PLW2901
@@ -508,7 +511,7 @@ def update_field(info: Info, instance: Model, field: models.Field, value: Any):
         and isinstance(field, models.ForeignObject)
         and not isinstance(value, Model)
     ):
-        value, data = _parse_pk(value, field.related_model)
+        value, data = _parse_pk(value, cast(type[Model], field.related_model))
 
     field.save_form_data(instance, value)
     # If data was passed to the foreign key, update it recursively
@@ -574,7 +577,9 @@ def update_m2m(
         existing = set(manager.all())
         need_remove_cache = need_remove_cache or bool(values)
         for v in values:
-            obj, data = _parse_data(info, manager.model, v, key_attr=key_attr)
+            obj, data = _parse_data(
+                info, cast(type[Model], manager.model), v, key_attr=key_attr
+            )
             if obj:
                 data.pop(key_attr, None)
                 through_defaults = data.pop("through_defaults", {})
@@ -632,7 +637,12 @@ def update_m2m(
     else:
         need_remove_cache = need_remove_cache or bool(value.add)
         for v in value.add or []:
-            obj, data = _parse_data(info, manager.model, v, key_attr=key_attr)
+            obj, data = _parse_data(
+                info,
+                cast(type[Model], manager.model),
+                v,
+                key_attr=key_attr,
+            )
             if obj and data:
                 data.pop(key_attr, None)
                 if full_clean:
@@ -653,7 +663,9 @@ def update_m2m(
 
         need_remove_cache = need_remove_cache or bool(value.remove)
         for v in value.remove or []:
-            obj, data = _parse_data(info, manager.model, v, key_attr=key_attr)
+            obj, data = _parse_data(
+                info, cast(type[Model], manager.model), v, key_attr=key_attr
+            )
             data.pop(key_attr, None)
             assert not data
             to_remove.append(obj)