diff --git a/lib/jekyll-spaceship/processors/mathjax-processor.rb b/lib/jekyll-spaceship/processors/mathjax-processor.rb
index 4c96f86..6f4d3ad 100644
--- a/lib/jekyll-spaceship/processors/mathjax-processor.rb
+++ b/lib/jekyll-spaceship/processors/mathjax-processor.rb
@@ -7,7 +7,6 @@ class MathjaxProcessor < Processor
     def self.config
       {
         'src' => [
-          'https://polyfill.io/v3/polyfill.min.js?features=es6',
           'https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js',
         ],
         'config' => {