diff --git a/requirements.txt b/requirements.txt
index d491281..970ce90 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,7 +13,7 @@ codespell
 
 
 # docs
-jupyter-book
+jupyter-book<2
 sphinx_design
 sphinx-book-theme>=1.0.1
 pydata-sphinx-theme>=0.13.3