diff --git a/doc/ext/custom_css.py b/doc/ext/custom_css.py
index cbaffcaba..6dc5d9ebd 100644
--- a/doc/ext/custom_css.py
+++ b/doc/ext/custom_css.py
@@ -13,4 +13,4 @@
 # under the License.
 
 def setup(app):
-    app.add_stylesheet('designate-docs.css')
+    app.add_css_file('designate-docs.css')
diff --git a/doc/ext/support_matrix.py b/doc/ext/support_matrix.py
index ecaab85ad..1631d28a9 100644
--- a/doc/ext/support_matrix.py
+++ b/doc/ext/support_matrix.py
@@ -442,8 +442,8 @@ def copy_assets(app, exception):
 
 
 def add_assets(app):
-    app.add_stylesheet('support-matrix.css')
-    app.add_javascript('support-matrix.js')
+    app.add_css_file('support-matrix.css')
+    app.add_js_file('support-matrix.js')
 
 
 def setup(app):