diff --git a/docs/conf.py b/docs/conf.py
index a1e63c0ad14..2c0bdacb6a2 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -75,9 +75,10 @@ def get_version():
 master_doc = 'index'
 
 latex_elements = {
-# Additional stuff for the LaTeX preamble.
-#'preamble': '',
-'preamble': r'''
+    # Additional stuff for the LaTeX preamble.
+    # 'preamble': '',
+    'preamble':
+    r'''
 \hypersetup{unicode=true}
 \usepackage{CJKutf8}
 \DeclareUnicodeCharacter{00A0}{\nobreakspace}
@@ -95,6 +96,7 @@ def get_version():
 ''',
 }
 
+
 def builder_inited_handler(app):
     subprocess.run(['./stat.py'])