diff --git a/doc/conf.py b/doc/conf.py
index 2f14165..4ac91ba 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -142,8 +142,8 @@ else:
 # further.  For a list of options available for each theme, see the
 # documentation.
 html_theme_options = dict(
-    github_url='https://github.com/python-escpos/python-escpos',
-    )
+    github_url="https://github.com/python-escpos/python-escpos",
+)
 
 # Add any paths that contain custom themes here, relative to this directory.
 # html_theme_path = []