diff --git a/environment.yml b/environment.yml
index 9e918d43d..a432c0f2d 100644
--- a/environment.yml
+++ b/environment.yml
@@ -8,7 +8,7 @@ dependencies:
   - pip:
     - jupyter-book==0.15.1
     - docutils==0.17.1
-    - quantecon-book-theme==0.4.1
+    - quantecon-book-theme==0.4.2
     - sphinx-tojupyter==0.3.0
     - sphinxext-rediraffe==0.2.7
     - sphinx-exercise==0.4.1