diff --git a/book/_config.yml b/book/_config.yml
index ff8c7bd..4e32db5 100644
--- a/book/_config.yml
+++ b/book/_config.yml
@@ -26,6 +26,7 @@ sphinx:
   - sphinx_prime_applets
   - sphinx_dropdown_toggle
   - sphinx_accessibility
+  - teachbooks_sphinx_tippy
   config:
     html_js_files:
     - https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.4/require.min.js