diff --git a/src/lmstudio/json_api.py b/src/lmstudio/json_api.py
index 3235258..83816be 100644
--- a/src/lmstudio/json_api.py
+++ b/src/lmstudio/json_api.py
@@ -1392,7 +1392,7 @@ def request_tool_call(
         def _call_requested_tool() -> ToolCallResultData:
             call_result = implementation(**kwds)
             return ToolCallResultData(
-                content=json.dumps(call_result), tool_call_id=tool_call_id
+                content=json.dumps(call_result, ensure_ascii=False), tool_call_id=tool_call_id
             )
 
         return _call_requested_tool