diff --git a/environment.yml b/environment.yml
index f9a57e7cf..5f05f8be9 100644
--- a/environment.yml
+++ b/environment.yml
@@ -6,8 +6,8 @@ dependencies:
   - anaconda=2022.10
   - pip
   - pip:
-    - jupyter-book
-    - quantecon-book-theme
+    - jupyter-book==0.13.2
+    - quantecon-book-theme==0.3.2
     - sphinx-tojupyter==0.2.1
     - sphinxext-rediraffe==0.2.7
     - sphinx-exercise==0.4.1