diff --git a/src/main.js b/src/main.js
index 2c86b9d9..85274948 100644
--- a/src/main.js
+++ b/src/main.js
@@ -26,10 +26,34 @@ import {BrawlView} from "./ui/web/BrawlView.js";
 import {Clock} from "./ui/web/dom/Clock.js";
 import {OnlineStatus} from "./ui/web/dom/OnlineStatus.js";
 
+function addScript(src) {
+    return new Promise(function (resolve, reject) {
+        var s = document.createElement("script");
+        s.setAttribute("src", src );
+        s.onload=resolve;
+        s.onerror=reject;
+        document.body.appendChild(s);
+    });
+}
+
+async function loadOlm(olmPaths) {
+    if (olmPaths) {
+        if (window.WebAssembly) {
+            await addScript(olmPaths.wasmBundle);
+            await window.Olm.init({locateFile: () => olmPaths.wasm});
+        } else {
+            await addScript(olmPaths.legacyBundle);
+            await window.Olm.init();
+        }
+        return window.Olm;
+    }
+    return null;
+}
+
 // Don't use a default export here, as we use multiple entries during legacy build,
 // which does not support default exports,
 // see https://github.com/rollup/plugins/tree/master/packages/multi-entry
-export async function main(container) {
+export async function main(container, olmPaths) {
     try {
         // to replay:
         // const fetchLog = await (await fetch("/fetchlogs/constrainterror.json")).json();
@@ -59,6 +83,7 @@ export async function main(container) {
                     sessionInfoStorage,
                     request,
                     clock,
+                    olmPromise: loadOlm(olmPaths),
                 });
             },
             sessionInfoStorage,
diff --git a/src/matrix/Session.js b/src/matrix/Session.js
index 7a7dea52..f6db9c97 100644
--- a/src/matrix/Session.js
+++ b/src/matrix/Session.js
@@ -21,7 +21,7 @@ import {User} from "./User.js";
 
 export class Session {
     // sessionInfo contains deviceId, userId and homeServer
-    constructor({storage, hsApi, sessionInfo}) {
+    constructor({storage, hsApi, sessionInfo, olm}) {
         this._storage = storage;
         this._hsApi = hsApi;
         this._session = null;
@@ -30,6 +30,7 @@ export class Session {
         this._sendScheduler = new SendScheduler({hsApi, backoff: new RateLimitingBackoff()});
         this._roomUpdateCallback = (room, params) => this._rooms.update(room.id, params);
         this._user = new User(sessionInfo.userId);
+        this._olm = olm;
     }
 
     async load() {
diff --git a/src/matrix/SessionContainer.js b/src/matrix/SessionContainer.js
index 74184a0a..eb025ec6 100644
--- a/src/matrix/SessionContainer.js
+++ b/src/matrix/SessionContainer.js
@@ -41,7 +41,7 @@ export const LoginFailure = createEnum(
 );
 
 export class SessionContainer {
-    constructor({clock, random, onlineStatus, request, storageFactory, sessionInfoStorage}) {
+    constructor({clock, random, onlineStatus, request, storageFactory, sessionInfoStorage, olmPromise}) {
         this._random = random;
         this._clock = clock;
         this._onlineStatus = onlineStatus;
@@ -57,6 +57,7 @@ export class SessionContainer {
         this._sync = null;
         this._sessionId = null;
         this._storage = null;
+        this._olmPromise = olmPromise;
     }
 
     createNewSessionId() {
@@ -149,7 +150,8 @@ export class SessionContainer {
             userId: sessionInfo.userId,
             homeServer: sessionInfo.homeServer,
         };
-        this._session = new Session({storage: this._storage, sessionInfo: filteredSessionInfo, hsApi});
+        const olm = await this._olmPromise;
+        this._session = new Session({storage: this._storage, sessionInfo: filteredSessionInfo, hsApi, olm});
         await this._session.load();
         
         this._sync = new Sync({hsApi, storage: this._storage, session: this._session});