diff --git a/package.json b/package.json
index 7b4ca05..93babd2 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
   "version": "0.0.0",
   "description": "A Node.js app demonstrating LaunchDarkly server-side bootstrapping.",
   "engines": {
-    "node": "16.13.1"
+    "node": ">=18"
   },
   "main": "index.js",
   "scripts": {
diff --git a/views/pages/index.ejs b/views/pages/index.ejs
index 00c43ea..d4b9060 100644
--- a/views/pages/index.ejs
+++ b/views/pages/index.ejs
@@ -10,31 +10,33 @@
       <li><code>bootstrapped client</code>: <span class="bootstrap">initializing…</span></li>
     </ul>
 
-    <script>
+    <script type="module">
+      import { createClient } from 'https://unpkg.com/@launchdarkly/js-client-sdk@4/dist/index.js';
+
       const context = window.ldContext;
-      console.log(`Clients initialized`);
-      const client = LDClient.initialize(window.ldClientsideId, context);
-      const bootstrapClient = LDClient.initialize(window.ldClientsideId, context, {
-        bootstrap: window.ldBootstrap
-      });
+      const client = createClient(window.ldClientsideId, context);
+      const bootstrapClient = createClient(window.ldClientsideId, context);
 
-      client.on('ready', handleUpdateNormalClient);
+      client.on('initialized', handleUpdateNormalClient);
       client.on('change', handleUpdateNormalClient);
-      bootstrapClient.on('ready', handleUpdateBootstrapClient);
+      bootstrapClient.on('initialized', handleUpdateBootstrapClient);
       bootstrapClient.on('change', handleUpdateBootstrapClient);
 
-      function handleUpdateNormalClient(){
-        console.log(`Normal SDK updated`);
+      function handleUpdateNormalClient() {
+        console.log('Normal SDK updated');
         render('.normal', client);
       }
-      function handleUpdateBootstrapClient(){
-        console.log(`Bootstrapped SDK updated`);
+      function handleUpdateBootstrapClient() {
+        console.log('Bootstrapped SDK updated');
         render('.bootstrap', bootstrapClient);
       }
-      
+
       function render(selector, targetClient) {
-        document.querySelector(selector).innerHTML = JSON.stringify(targetClient.allFlags(context), null, 2);
+        document.querySelector(selector).innerHTML = JSON.stringify(targetClient.allFlags(), null, 2);
       }
+
+      client.start().catch(console.error);
+      bootstrapClient.start({ bootstrap: window.ldBootstrap }).catch(console.error);
     </script>
   </body>
 </html>
diff --git a/views/partials/header.ejs b/views/partials/header.ejs
index 4bfbc83..516e259 100644
--- a/views/partials/header.ejs
+++ b/views/partials/header.ejs
@@ -1,9 +1,6 @@
 <title>LaunchDarkly server-side bootstrapping demo</title>
 <meta charset="utf-8">
 <meta http-equiv="X-UA-Compatible" content="IE=edge;chrome=1" />
-<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.auto.min.js"></script>
-<script src="https://unpkg.com/event-source-polyfill@0.0.12/src/eventsource.min.js"></script>
-<script src="https://unpkg.com/launchdarkly-js-client-sdk@3"></script>
 <script>
     window.ldBootstrap=<%-JSON.stringify(allFlags)%>
     window.ldClientsideId="<%=clientsideId%>"