diff --git a/src/openai/types/chat/chat_completion_custom_tool_param.py b/src/openai/types/chat/chat_completion_custom_tool_param.py
index 14959ee449..1dc2c41aef 100644
--- a/src/openai/types/chat/chat_completion_custom_tool_param.py
+++ b/src/openai/types/chat/chat_completion_custom_tool_param.py
@@ -2,57 +2,22 @@
 
 from __future__ import annotations
 
-from typing import Union
-from typing_extensions import Literal, Required, TypeAlias, TypedDict
+from typing_extensions import Literal, Required, TypedDict
 
-__all__ = [
-    "ChatCompletionCustomToolParam",
-    "Custom",
-    "CustomFormat",
-    "CustomFormatText",
-    "CustomFormatGrammar",
-    "CustomFormatGrammarGrammar",
-]
+from ..shared_params.custom_tool_input_format import CustomToolInputFormat
 
+__all__ = ["ChatCompletionCustomToolParam"]
 
-class CustomFormatText(TypedDict, total=False):
-    type: Required[Literal["text"]]
-    """Unconstrained text format. Always `text`."""
 
-
-class CustomFormatGrammarGrammar(TypedDict, total=False):
-    definition: Required[str]
-    """The grammar definition."""
-
-    syntax: Required[Literal["lark", "regex"]]
-    """The syntax of the grammar definition. One of `lark` or `regex`."""
-
-
-class CustomFormatGrammar(TypedDict, total=False):
-    grammar: Required[CustomFormatGrammarGrammar]
-    """Your chosen grammar."""
-
-    type: Required[Literal["grammar"]]
-    """Grammar format. Always `grammar`."""
-
-
-CustomFormat: TypeAlias = Union[CustomFormatText, CustomFormatGrammar]
-
-
-class Custom(TypedDict, total=False):
+class ChatCompletionCustomToolParam(TypedDict, total=False):
     name: Required[str]
     """The name of the custom tool, used to identify it in tool calls."""
 
+    type: Required[Literal["custom"]]
+    """The type of the custom tool. Always `custom`."""
+
     description: str
     """Optional description of the custom tool, used to provide more context."""
 
-    format: CustomFormat
+    format: CustomToolInputFormat
     """The input format for the custom tool. Default is unconstrained text."""
-
-
-class ChatCompletionCustomToolParam(TypedDict, total=False):
-    custom: Required[Custom]
-    """Properties of the custom tool."""
-
-    type: Required[Literal["custom"]]
-    """The type of the custom tool. Always `custom`."""