diff --git a/jupyter-book/conditions/compositional.yml b/jupyter-book/conditions/compositional.yml
index f85032e1..67435b59 100644
--- a/jupyter-book/conditions/compositional.yml
+++ b/jupyter-book/conditions/compositional.yml
@@ -16,5 +16,5 @@ dependencies:
   - pip
   - pip:
       - altair==4.2.0
-      - pertpy==0.9.0
+      - pertpy==0.8.0
       - toytree==2.0.1