diff --git a/doc/conf.py b/doc/conf.py
index b6edc07f612..65635353e93 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -351,4 +351,5 @@
     "numba": ("https://numba.pydata.org/numba-doc/latest", None),
     "matplotlib": ("https://matplotlib.org", None),
     "dask": ("https://docs.dask.org/en/latest", None),
+    "cftime": ("https://unidata.github.io/cftime", None),
 }