diff --git a/examples/03_markdown/01_markdown.py b/examples/03_markdown/01_markdown.py
index 94857b2b..ff317544 100644
--- a/examples/03_markdown/01_markdown.py
+++ b/examples/03_markdown/01_markdown.py
@@ -23,7 +23,7 @@
 @state.change("file_name")
 def update_md(file_name, **kwargs):
     md_file_path = os.path.join(os.path.dirname(__file__), file_name)
-    with open(md_file_path, encoding='utf-8') as md:
+    with open(md_file_path, encoding="utf-8") as md:
         ctrl.md_update(md.read())