diff --git a/examples/demo_opts.py b/examples/demo_opts.py
index d118306..f6eddf6 100755
--- a/examples/demo_opts.py
+++ b/examples/demo_opts.py
@@ -1,3 +1,4 @@
+#！/usr/bin/env python
 # -*- coding: utf-8 -*-
 # Copyright (c) 2014-2022 Richard Hull and contributors
 # See LICENSE.rst for details.