diff --git a/mkdocs.yml b/mkdocs.yml
index e51872f7d..6019dc26a 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -142,7 +142,6 @@ markdown_extensions:
 
 extra_javascript:
   - javascripts/mathjax.js
-  - https://polyfill.io/v3/polyfill.min.js?features=es6
   - https://cdnjs.cloudflare.com/ajax/libs/mathjax/3.2.2/es5/tex-mml-chtml.min.js
   # - javascripts/katex.js 
   # - https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.16.7/katex.min.js