diff --git a/themes/pure-ejs/layouts/partials/head.html b/themes/pure-ejs/layouts/partials/head.html
index 0f0b2ceb..9c4d6a26 100644
--- a/themes/pure-ejs/layouts/partials/head.html
+++ b/themes/pure-ejs/layouts/partials/head.html
@@ -5,7 +5,7 @@
 <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
 <!-- Chrome, Firefox OS and Opera Status Bar Color -->
 <meta name="theme-color" content="#FFFFFF">
-<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.16.0/katex.min.css">
+<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.11.1/katex.min.css">
 <link rel="stylesheet" type="text/css"
   href="https://cdnjs.cloudflare.com/ajax/libs/prism/1.19.0/themes/prism.min.css">
 <link rel="stylesheet" type="text/css" href="css/SourceSansPro.css">