diff --git a/section06/80_creating_image_upload_resource/end/schemas/image.py b/section06/80_creating_image_upload_resource/end/schemas/image.py
index 9e1f2b0..0775429 100644
--- a/section06/80_creating_image_upload_resource/end/schemas/image.py
+++ b/section06/80_creating_image_upload_resource/end/schemas/image.py
@@ -1,3 +1,4 @@
+from typing import Union
 from marshmallow import Schema, fields
 from werkzeug.datastructures import FileStorage
 
@@ -7,7 +8,7 @@ class FileStorageField(fields.Field):
         "invalid": "Not a valid image."
     }
 
-    def _deserialize(self, value, attr, data, **kwargs) -> FileStorage:
+    def _deserialize(self, value, attr, data, **kwargs) -> Union[FileStorage, None]:
         if value is None:
             return None