From a53475a3fe4cd089606f8e0d7c06b21fd9a77cc1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Lafr=C3=A9choux?=
 <jlafrechoux@nobatek.inef4.com>
Date: Thu, 28 Oct 2021 08:49:30 +0200
Subject: [PATCH] typing.cast field_obj.attribute

---
 src/marshmallow/schema.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/marshmallow/schema.py b/src/marshmallow/schema.py
index a8dc6ce04..13653baf7 100644
--- a/src/marshmallow/schema.py
+++ b/src/marshmallow/schema.py
@@ -663,7 +663,7 @@ def _deserialize(
                     index=index,
                 )
                 if value is not missing:
-                    key = field_obj.attribute
+                    key = typing.cast(str, field_obj.attribute)
                     set_value(ret_d, key, value)
             if unknown != EXCLUDE:
                 fields = {field_obj.data_key for field_obj in self.load_fields.values()}