diff --git a/book/_config.yml b/book/_config.yml
index 702234a..c8d6b2e 100644
--- a/book/_config.yml
+++ b/book/_config.yml
@@ -31,6 +31,7 @@ sphinx:
     - jupyterbook_patches
     - download_link_replacer
     - sphinx.ext.extlinks
+    - sphinx_image_inverter
 
 bibtex_bibfiles: 
   - references.bib
diff --git a/requirements.txt b/requirements.txt
index 30a25f4..f585a27 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 # first list the packages you wish to download from PyPI
 teachbooks # depends on jupyter-book
 jupyterbook-patches
+sphinx-image-inverter
 # numpy
 
 # docutils version for reference page formatting