diff --git a/docs/index.html b/docs/index.html
index 9a60a59..b2edb61 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -2,6 +2,7 @@
 <html>
   <head>
     <title>go-wasm-http-server demo</title>
+    <script src="https://cdn.jsdelivr.net/gh/nlepage/go-wasm-http-server@b4be701615d284296a4a1aaa852db02f139969ee/index.js"></script>
     <script>
       async function hello() {
         res=await fetch('api/hello', {
diff --git a/index.js b/index.js
index f35a13a..b8ba0f5 100644
--- a/index.js
+++ b/index.js
@@ -1,9 +1,11 @@
+const swUrl = 'https://cdn.jsdelivr.net/gh/nlepage/go-wasm-http-server@b4be701615d284296a4a1aaa852db02f139969ee/index.js'
+
 window.wasmhttp = {
   register: async (wasm, { scope, base = '' } = {}) => {
     const options = {}
     if (scope) options.scope = scope
     //FIXME register once
-    const registration = await navigator.serviceWorker.register('sw.js', options)
+    const registration = await navigator.serviceWorker.register(swUrl, options)
     await navigator.serviceWorker.ready
     registration.active.postMessage({
       type: 'wasmhttp.register',
