diff --git a/libs/partners/openai/langchain_openai/chat_models/base_v1.py b/libs/partners/openai/langchain_openai/chat_models/base_v1.py
index a75e2c99772..14066004718 100644
--- a/libs/partners/openai/langchain_openai/chat_models/base_v1.py
+++ b/libs/partners/openai/langchain_openai/chat_models/base_v1.py
@@ -2883,7 +2883,7 @@ def _lc_tool_call_to_openai_tool_call(tool_call: ToolCall) -> dict:
         "id": tool_call["id"],
         "function": {
             "name": tool_call["name"],
-            "arguments": json.dumps(tool_call["args"]),
+            "arguments": json.dumps(tool_call["args"], ensure_ascii=False),
         },
     }