diff --git a/docs/conf.py b/docs/conf.py
index c18255998..e3889c31d 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -167,11 +167,8 @@
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
-html_context = {
-    'css_files': [
-        '_static/theme_overrides.css',  # override wide tables in RTD theme
-    ],
- }
+def setup(app):
+    app.add_stylesheet("theme_overrides.css")
 
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied