diff --git a/docs/conf.py b/docs/conf.py
index acff208..8a59a4e 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -124,6 +124,7 @@
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
+html_css_files = ['custom.css']
 
 # Custom sidebar templates, must be a dictionary that maps document names
 # to template names.