diff --git a/docs/source/conf.py b/docs/source/conf.py
index d5d369d2..420fb66e 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -352,4 +352,5 @@
     'python': ('https://docs.python.org/3/', None),
     'numpy': ('https://numpy.org/doc/stable/', None),
     'scipy': ('https://docs.scipy.org/doc/scipy/', None),
+    'checkpoint_schedules': ('https://www.firedrakeproject.org/checkpoint_schedules/', None),
 }