diff --git a/index.html b/index.html
index b60ab0a..708c782 100644
--- a/index.html
+++ b/index.html
@@ -14,7 +14,7 @@
 
 <!-- CodeMirror syntax highlighting - this is optional -->
 <script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.61.1/codemirror.min.js"></script>
-<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.33.0/codemirror.css">
+<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.61.1/codemirror.css">
 <script src="cm/basic.js"></script>
 <link rel="stylesheet" href="cm/basic.css">
 <style>