diff --git a/environment.yml b/environment.yml
index fb683c800..98007aadc 100644
--- a/environment.yml
+++ b/environment.yml
@@ -8,7 +8,7 @@ dependencies:
   - pip:
     - jupyter-book==0.10.2
     - sphinx-multitoc-numbering==0.1.3
-    - quantecon-book-theme==0.1.7
+    - quantecon-book-theme==0.2.1
     - sphinx-tojupyter==0.1.1
     - sphinxext-rediraffe==0.2.7
     - sphinx-exercise==0.1.1
diff --git a/lectures/_config.yml b/lectures/_config.yml
index 27a984df0..b76a173b3 100644
--- a/lectures/_config.yml
+++ b/lectures/_config.yml
@@ -56,7 +56,7 @@ sphinx:
         Macros:
           "argmax" : "arg\\,max"
           "argmin" : "arg\\,min"
-    mathjax_path: https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js
+    mathjax_path: https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-svg.js
     rediraffe_redirects:
       index_toc.md: intro.md
     tojupyter_static_file_path: ["source/_static", "_static"]