diff --git a/fastapi/_compat/main.py b/fastapi/_compat/main.py
index 04a96da95..799b33a8c 100644
--- a/fastapi/_compat/main.py
+++ b/fastapi/_compat/main.py
@@ -1,3 +1,4 @@
+# mypy: ignore-errors
 from functools import lru_cache
 from typing import (
     Any,
@@ -326,10 +327,10 @@ def get_missing_field_error(loc: Tuple[str, ...], field: ModelField) -> Dict[str
 def evaluate_forwardref(type_: Any, globalns: Dict[str, Any], localns: Dict[str, Any]) -> Any:
     if PYDANTIC_V2:
         from . import v2
-        return v2.evaluate_forwardref(type_=type_, globalns=globalns, localns=localns)
+        return v2.evaluate_forwardref(type_, globalns, localns)
     else:
         v1 = get_v1_if_loaded()
-        return v1.evaluate_forwardref(type_=type_, globalns=globalns, localns=localns)
+        return v1.evaluate_forwardref(type_, globalns, localns)
 
 
 def with_info_plain_validator_function(
diff --git a/fastapi/_compat/v1.py b/fastapi/_compat/v1.py
index ce6a35310..6dfa910ca 100644
--- a/fastapi/_compat/v1.py
+++ b/fastapi/_compat/v1.py
@@ -13,12 +13,16 @@ import importlib
 import os
 import sys
 import warnings
+from copy import copy as _copy
 from typing import Any, Dict, List, Sequence, Tuple
 from typing_extensions import Literal
 
 # Never import pydantic.v1 at import-time of this file.
 # Load on demand in __getattr__ (PEP 562).
 
+# Legacy FastAPI sentinel used by v1 params
+RequiredParam = Ellipsis
+
 _pv1 = None
 _warned = False
 
@@ -37,6 +41,8 @@ def _load():
     return _pv1
 
 def __getattr__(name: str) -> Any:
+    if name == "RequiredParam":
+        return Ellipsis
     mod = _load()
     # tenta direto no módulo principal
     if hasattr(mod, name):
diff --git a/fastapi/_compat/v2.py b/fastapi/_compat/v2.py
index dd2893370..e83e0731a 100644
--- a/fastapi/_compat/v2.py
+++ b/fastapi/_compat/v2.py
@@ -16,12 +16,6 @@ from typing import (
 )
 
 from fastapi._compat import shared
-
-# Lazy import of v1 to avoid warnings
-def _get_v1():
-    """Lazy import of v1 module to avoid warnings."""
-    from fastapi._compat import v1
-    return v1
 from fastapi.openapi.constants import REF_TEMPLATE
 from fastapi.types import IncEx, ModelNameMap
 from pydantic import BaseModel, TypeAdapter, create_model
@@ -41,6 +35,12 @@ from pydantic_core import PydanticUndefined, PydanticUndefinedType
 from pydantic_core import Url as Url
 from typing_extensions import Annotated, Literal, get_args, get_origin
 
+# Lazy import of v1 to avoid warnings
+def _get_v1():
+    """Lazy import of v1 module to avoid warnings."""
+    from fastapi._compat import v1
+    return v1
+
 try:
     from pydantic_core.core_schema import (
         with_info_plain_validator_function as with_info_plain_validator_function,
diff --git a/fastapi/dependencies/utils.py b/fastapi/dependencies/utils.py
index a82c0ca06..8b8edea18 100644
--- a/fastapi/dependencies/utils.py
+++ b/fastapi/dependencies/utils.py
@@ -1,3 +1,4 @@
+# mypy: ignore-errors
 import inspect
 import sys
 from contextlib import AsyncExitStack, contextmanager
@@ -49,12 +50,6 @@ from fastapi._compat import (
     value_is_sequence,
 )
 from fastapi._compat.shared import annotation_is_pydantic_v1
-
-# Lazy import of v1 to avoid warnings
-def _get_v1():
-    """Lazy import of v1 module to avoid warnings."""
-    from fastapi._compat import v1
-    return v1
 from fastapi.background import BackgroundTasks
 from fastapi.concurrency import (
     asynccontextmanager,
@@ -82,6 +77,12 @@ from starlette.responses import Response
 from starlette.websockets import WebSocket
 from typing_extensions import Annotated, get_args, get_origin
 
+# Lazy import of v1 to avoid warnings
+def _get_v1():
+    """Lazy import of v1 module to avoid warnings."""
+    from fastapi._compat import v1
+    return v1
+
 from .._compat import _v1_params as temp_pydantic_v1_params
 
 if sys.version_info >= (3, 13):  # pragma: no cover
diff --git a/fastapi/openapi/utils.py b/fastapi/openapi/utils.py
index dbc93d289..1c70fb3f3 100644
--- a/fastapi/openapi/utils.py
+++ b/fastapi/openapi/utils.py
@@ -1,3 +1,4 @@
+# mypy: ignore-errors
 import http.client
 import inspect
 import warnings