diff --git a/demo/index.html b/demo/index.html
index bf26c67..0d12e75 100644
--- a/demo/index.html
+++ b/demo/index.html
@@ -4,8 +4,8 @@
         <meta charset="utf-8">
         <title>Supercluster Leaflet demo</title>
 
-        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.0.3/leaflet.css" />
-        <script src="https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.0.3/leaflet.js"></script>
+        <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.3/dist/leaflet.css" integrity="sha256-kLaT2GOSpHechhsozzB+flnD+zUyjE2LlfWPgU04xyI=" crossorigin="" />
+        <script src="https://unpkg.com/leaflet@1.9.3/dist/leaflet.js" integrity="sha256-WBkoXOwTeyKclOHuWtc+i2uENFpDZ9YPdf5Hf+D7ewM=" crossorigin=""></script>
 
         <link rel="stylesheet" href="cluster.css" />