diff --git a/api/controllers/files/tool_files.py b/api/controllers/files/tool_files.py
index 7cb97806c8..2779514bed 100644
--- a/api/controllers/files/tool_files.py
+++ b/api/controllers/files/tool_files.py
@@ -1,3 +1,5 @@
+from urllib.parse import quote
+
 from flask import Response
 from flask_restful import Resource, reqparse  # type: ignore
 from werkzeug.exceptions import Forbidden, NotFound
@@ -46,7 +48,8 @@ class ToolFilePreviewApi(Resource):
         if tool_file.size > 0:
             response.headers["Content-Length"] = str(tool_file.size)
         if args["as_attachment"]:
-            response.headers["Content-Disposition"] = f"attachment; filename={tool_file.name}"
+            encoded_filename = quote(tool_file.name)
+            response.headers["Content-Disposition"] = f"attachment; filename*=UTF-8''{encoded_filename}"
 
         return response
 
diff --git a/api/core/tools/tool_file_manager.py b/api/core/tools/tool_file_manager.py
index c60e4f4e4a..b849f51064 100644
--- a/api/core/tools/tool_file_manager.py
+++ b/api/core/tools/tool_file_manager.py
@@ -4,6 +4,7 @@ import hmac
 import logging
 import os
 import time
+from collections.abc import Generator
 from mimetypes import guess_extension, guess_type
 from typing import Optional, Union
 from uuid import uuid4
@@ -215,7 +216,7 @@ class ToolFileManager:
 
         return blob, tool_file.mimetype
 
-    def get_file_generator_by_tool_file_id(self, tool_file_id: str):
+    def get_file_generator_by_tool_file_id(self, tool_file_id: str) -> tuple[Optional[Generator], Optional[ToolFile]]:
         """
         get file binary