From f2f4983199e9e7c77b4edccd380855efca5ca6f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebasti=C3=A1n=20Ram=C3=ADrez?= <tiangolo@gmail.com>
Date: Sat, 20 Dec 2025 14:18:30 +0100
Subject: [PATCH] =?UTF-8?q?=F0=9F=94=A5=20Remove=20conditional=20with=20da?=
 =?UTF-8?q?taclasses=20that=20would=20only=20happen=20in=20Pydantic=20v1?=
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---
 fastapi/utils.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/fastapi/utils.py b/fastapi/utils.py
index 425ac1fbd..42feb171c 100644
--- a/fastapi/utils.py
+++ b/fastapi/utils.py
@@ -1,7 +1,6 @@
 import re
 import warnings
 from collections.abc import MutableMapping
-from dataclasses import is_dataclass
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -150,8 +149,6 @@ def create_cloned_field(
         cloned_types = _CLONED_TYPES_CACHE
 
     original_type = field.type_
-    if is_dataclass(original_type) and hasattr(original_type, "__pydantic_model__"):
-        original_type = original_type.__pydantic_model__
     use_type = original_type
     if lenient_issubclass(original_type, v1.BaseModel):
         original_type = cast(type[v1.BaseModel], original_type)