diff --git a/_includes/head.html b/_includes/head.html
index 9524520..5fe5873 100644
--- a/_includes/head.html
+++ b/_includes/head.html
@@ -17,7 +17,6 @@
 
 {% if page.usemathjax %}
   <!-- for mathjax support -->
-  <script src="https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js"></script>
   <script id="MathJax-script" async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/3.2.2/es5/tex-mml-chtml.min.js"></script>
 {% endif %}
 </head>