diff --git a/src/mcp/server/fastmcp/server.py b/src/mcp/server/fastmcp/server.py
index d1550bc9c..f6edd1267 100644
--- a/src/mcp/server/fastmcp/server.py
+++ b/src/mcp/server/fastmcp/server.py
@@ -552,7 +552,8 @@ def _convert_to_content(
 
     if not isinstance(result, str):
         try:
-            result = json.dumps(pydantic_core.to_jsonable_python(result))
+            result = json.dumps(pydantic_core.to_jsonable_python(result)
+                                , ensure_ascii=False)
         except Exception:
             result = str(result)