diff --git a/index.js b/index.js
index dec6957..74036b2 100755
--- a/index.js
+++ b/index.js
@@ -4,13 +4,13 @@
 
 hexo.config.math = Object.assign({
   katex: {
-    css: 'https://cdn.jsdelivr.net/npm/katex@0.12.0/dist/katex.min.css',
+    css: 'https://fastly.jsdelivr.net/npm/katex@0.12.0/dist/katex.min.css',
     options: {
       throwOnError: false
     }
   },
   mathjax: {
-    css: 'https://cdn.jsdelivr.net/npm/hexo-math@4.0.0/dist/style.css',
+    css: 'https://fastly.jsdelivr.net/npm/hexo-math@4.0.0/dist/style.css',
     options: {
       // https://docs.mathjax.org/en/latest/web/typeset.html#conversion-options
       conversion: {
diff --git a/test/index.js b/test/index.js
index ec3bd71..b1792fa 100755
--- a/test/index.js
+++ b/test/index.js
@@ -12,14 +12,14 @@ describe('hexo-math', () => {
     math: {
       katex: {
         enable: true,
-        css: 'https://cdn.jsdelivr.net/npm/katex@0.12.0/dist/katex.min.css',
+        css: 'https://fastly.jsdelivr.net/npm/katex@0.12.0/dist/katex.min.css',
         options: {
           throwOnError: false
         }
       },
       mathjax: {
         enable: true,
-        css: 'https://cdn.jsdelivr.net/gh/hexojs/hexo-math/master/dist/style.css',
+        css: 'https://fastly.jsdelivr.net/gh/hexojs/hexo-math/master/dist/style.css',
         options: {
           conversion: {
             display: false