diff --git a/web/index.html b/web/index.html
index 9856c7a..84569da 100644
--- a/web/index.html
+++ b/web/index.html
@@ -39,22 +39,22 @@
     Strategy: load olm.js synchronously, await Olm.init(), THEN inject
     flutter_bootstrap.js dynamically so Flutter never starts before Olm.
   -->
-  <script src="olm.js"></script>
   <script>
-    Olm.init({ locateFile: function() { return 'olm.wasm'; } })
-      .then(function() {
-        var s = document.createElement('script');
-        s.src = 'flutter_bootstrap.js';
-        document.body.appendChild(s);
-      })
-      .catch(function(e) {
-        // Olm failed — start Flutter anyway so user sees an error screen
-        // rather than a blank page.
-        console.warn('[M8Chat] Olm init failed:', e);
-        var s = document.createElement('script');
-        s.src = 'flutter_bootstrap.js';
-        document.body.appendChild(s);
+    // Unregister any stale service worker from previous builds — cached old JS
+    // causes calls and features to use outdated code silently.
+    if ('serviceWorker' in navigator) {
+      navigator.serviceWorker.getRegistrations().then(function(registrations) {
+        for (var r of registrations) { r.unregister(); }
       });
+    }
   </script>
+  <!--
+    Olm (E2EE) disabled for Phase 1 web builds. The Matrix SDK gracefully
+    skips encryption when Olm is not loaded — unencrypted rooms work fine.
+    E2EE requires persistent Olm account storage (IndexedDB) to avoid
+    device key conflicts on /keys/upload (400). Deferred to Phase 3.
+    The olm.js and olm.wasm files remain deployed for future use.
+  -->
+  <script src="flutter_bootstrap.js" async></script>
 </body>
 </html>