diff --git a/nbsite/shared_conf.py b/nbsite/shared_conf.py
index 5ecefa4..0655f6b 100644
--- a/nbsite/shared_conf.py
+++ b/nbsite/shared_conf.py
@@ -54,6 +54,7 @@ def remove_mystnb_static(app):
     'sphinx.ext.linkcode',
     'sphinx.ext.inheritance_diagram',
     'sphinx_copybutton',
+    'sphinxext.rediraffe',
 ]
 
 # Default theme is the PyData Sphinx Theme
diff --git a/setup.py b/setup.py
index 5d0f7d8..d45c231 100644
--- a/setup.py
+++ b/setup.py
@@ -71,6 +71,7 @@ def get_setup_version(root, reponame):
         'myst-parser',
         'sphinx-copybutton',
         'sphinx-design',
+        'sphinxext-rediraffe',
         'urllib3 <2.0.0',
     ],
     extras_require= {