diff --git a/docs/requirements.txt b/docs/requirements.txt
index 67f20aa..f06c48a 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -15,3 +15,4 @@ sphinx-autodoc-typehints
 sphinx-automodapi
 piccolo-theme
 autodocsumm
+sphinx_book_theme