diff --git a/mathjax.install b/mathjax.install
index 1e73a04..49459ad 100644
--- a/mathjax.install
+++ b/mathjax.install
@@ -88,3 +88,16 @@ EOD;
     variable_set('mathjax_config_string', $str);
   }
 }
+
+/**
+ * Update the CDN URL.
+ */
+function mathjax_update_7201() {
+  $url = variable_get('mathjax_cdn_url');
+  $new = 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js';
+  $old = 'https://cdn.mathjax.org/mathjax/latest/MathJax.js';
+  if (strpos($url, $old) !== FALSE) {
+    $url = str_replace($old, $new, $url);
+    variable_set('mathjax_cdn_url', $url);
+  }
+}
diff --git a/mathjax.module b/mathjax.module
index 5485170..50913cc 100644
--- a/mathjax.module
+++ b/mathjax.module
@@ -44,7 +44,7 @@ function mathjax_menu() {
 function mathjax_default($parameter) {
   switch ($parameter) {
     case 'cdn url':
-      return 'https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML';
+      return 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS-MML_HTMLorMML';
 
     case 'config string':
       return "