diff --git a/book/_config.yml b/book/_config.yml
index 770788e..dc76afc 100644
--- a/book/_config.yml
+++ b/book/_config.yml
@@ -52,6 +52,7 @@ sphinx:                                              # Options passed on to the
     - sphinx_proof                                   # Allows you to add various mathy admonitions to your book: https://sphinx-proof.readthedocs.io/en/latest/
     - sphinx_code_examples                           # Allows you to include code blocks in examples: https://teachbooks.io/manual/_git/github.com_TeachBooks_sphinx-code-examples/main/MANUAL.html
     - sphinx_accessibility                           # Allows dyslexic-friendly fonts and high contrast mode: https://teachbooks.io/manual/accessibility/_git/github.com_TeachBooks_Sphinx-Accessibility/manual/README.html
+    - teachbooks_sphinx_tippy                        # Adds rich hoover-over tips https://teachbooks.io/manual/external/teachbooks-sphinx-tippy/README.html
 
 
 bibtex_bibfiles: 
diff --git a/requirements.txt b/requirements.txt
index 91b3dc4..824a53d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,6 +12,7 @@ git+https://github.com/TeachBooks/sphinx-togglebutton #waiting for merge of http
 git+https://github.com/TeachBooks/sphinx-proof #waiting for merge of https://github.com/executablebooks/sphinx-proof/pull/146, after, replace this line with `sphinx-proof`
 sphinx-code-examples
 sphinx-accessibility
+teachbooks-sphinx-tippy
 
 # Now list the packages you want to download directly from GitHub
 git+https://github.com/TeachBooks/Sphinx-Thebe