diff --git a/backend/open_webui/__init__.py b/backend/open_webui/__init__.py
index acb70e17e2..be25227d36 100644
--- a/backend/open_webui/__init__.py
+++ b/backend/open_webui/__init__.py
@@ -2,18 +2,17 @@ import base64
 import os
 import random
 from pathlib import Path
+from typing import Annotated
 
 import typer
 import uvicorn
-from typing import Optional
-from typing_extensions import Annotated
 
 app = typer.Typer()
 
 KEY_FILE = Path.cwd() / '.webui_secret_key'
 
 
-def version_callback(value: bool):
+def version_callback(value: bool) -> None:
     if value:
         from open_webui.env import VERSION
 
@@ -23,7 +22,7 @@ def version_callback(value: bool):
 
 @app.command()
 def main(
-    version: Annotated[Optional[bool], typer.Option('--version', callback=version_callback)] = None,
+    version: Annotated[bool | None, typer.Option('--version', callback=version_callback)] = None,
 ):
     pass
 
@@ -66,7 +65,7 @@ def serve(
             os.environ['USE_CUDA_DOCKER'] = 'false'
             os.environ['LD_LIBRARY_PATH'] = ':'.join(LD_LIBRARY_PATH)
 
-    import open_webui.main  # we need set environment variables before importing main
+    import open_webui.main  # noqa: F401
     from open_webui.env import UVICORN_WORKERS  # Import the workers setting
 
     uvicorn.run(