diff --git a/libs/prebuilt/langgraph/prebuilt/tool_node.py b/libs/prebuilt/langgraph/prebuilt/tool_node.py
index c266684be..a45453b2e 100644
--- a/libs/prebuilt/langgraph/prebuilt/tool_node.py
+++ b/libs/prebuilt/langgraph/prebuilt/tool_node.py
@@ -34,6 +34,7 @@ Typical Usage:
 import asyncio
 import inspect
 import json
+import warnings
 from copy import copy, deepcopy
 from dataclasses import replace
 from typing import (
@@ -1342,3 +1343,4 @@ def _get_runtime_arg(tool: BaseTool) -> Optional[str]:
 
 
 
+