diff --git a/docs/source/conf.py b/docs/source/conf.py
index b3627f5..8eb6864 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -58,9 +58,9 @@
 # Undocumented trick: if we def setup here in conf.py, it gets called just
 # like an extension's setup function.
 def setup(app):
-    app.add_javascript("show-code.js")
-    app.add_javascript("facebox.js")
-    app.add_stylesheet("facebox.css")
+    app.add_js_file("show-code.js")
+    app.add_js_file("facebox.js")
+    app.add_css_file("facebox.css")
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
diff --git a/newsfragments/200.bugfix.rst b/newsfragments/200.bugfix.rst
new file mode 100644
index 0000000..681040e
--- /dev/null
+++ b/newsfragments/200.bugfix.rst
@@ -0,0 +1 @@
+Fix documentation builds with Sphinx 9 and later.