diff --git a/src/crypto/DeviceList.js b/src/crypto/DeviceList.js
index 1a213a416..3e7e1a4ff 100644
--- a/src/crypto/DeviceList.js
+++ b/src/crypto/DeviceList.js
@@ -59,8 +59,9 @@ const TRACKING_STATUS_UP_TO_DATE = 3;
  * @alias module:crypto/DeviceList
  */
 export default class DeviceList {
-    constructor(baseApis, cryptoStore, olmDevice) {
+    constructor(baseApis, cryptoStore, sessionStore, olmDevice) {
         this._cryptoStore = cryptoStore;
+        this._sessionStore = sessionStore;
 
         // userId -> {
         //     deviceId -> {
@@ -96,16 +97,37 @@ export default class DeviceList {
      * Load the device tracking state from storage
      */
     async load() {
+        let shouldDeleteSessionStore = false;
         await this._cryptoStore.doTxn(
-            'readonly', [IndexedDBCryptoStore.STORE_DEVICE_DATA], (txn) => {
+            // migrate from session store if there's data there and not here
+            'readwrite', [IndexedDBCryptoStore.STORE_DEVICE_DATA], (txn) => {
                 this._cryptoStore.getEndToEndDeviceData(txn, (deviceData) => {
-                    this._devices = deviceData ? deviceData.devices : {},
-                    this._deviceTrackingStatus = deviceData ?
-                        deviceData.trackingStatus : {};
-                    this._syncToken = deviceData ? deviceData.syncToken : null;
+                    if (deviceData === null) {
+                        console.log("Migrating e2e device data...");
+                        this._devices = this._sessionStore.getAllEndToEndDevices();
+                        this._deviceTrackingStatus = this._sessionStore.getEndToEndDeviceTrackingStatus();
+                        this._syncToken = this._sessionStore.getEndToEndDeviceSyncToken();
+                        this._cryptoStore.storeEndToEndDeviceData({
+                            devices: this._devices,
+                            trackingStatus: this._deviceTrackingStatus,
+                            syncToken: this._syncToken,
+                        }, txn);
+                        shouldDeleteSessionStore = true;
+                    } else {
+                        this._devices = deviceData ? deviceData.devices : {},
+                        this._deviceTrackingStatus = deviceData ?
+                            deviceData.trackingStatus : {};
+                        this._syncToken = deviceData ? deviceData.syncToken : null;
+                    }
                 });
             },
         );
+
+        if (shouldDeleteSessionStore) {
+            // migrated data is now safely persisted: remove from old store
+            this._sessionStore.removeEndToEndDeviceData();
+        }
+
         for (const u of Object.keys(this._deviceTrackingStatus)) {
             // if a download was in progress when we got shut down, it isn't any more.
             if (this._deviceTrackingStatus[u] == TRACKING_STATUS_DOWNLOAD_IN_PROGRESS) {
diff --git a/src/crypto/index.js b/src/crypto/index.js
index 3a8b05d09..d1bee2fd4 100644
--- a/src/crypto/index.js
+++ b/src/crypto/index.js
@@ -69,7 +69,7 @@ function Crypto(baseApis, sessionStore, userId, deviceId,
     this._cryptoStore = cryptoStore;
 
     this._olmDevice = new OlmDevice(sessionStore, cryptoStore);
-    this._deviceList = new DeviceList(baseApis, cryptoStore, this._olmDevice);
+    this._deviceList = new DeviceList(baseApis, cryptoStore, sessionStore, this._olmDevice);
 
     // the last time we did a check for the number of one-time-keys on the
     // server.
diff --git a/src/store/session/webstorage.js b/src/store/session/webstorage.js
index 0fa813a27..8ea149beb 100644
--- a/src/store/session/webstorage.js
+++ b/src/store/session/webstorage.js
@@ -68,43 +68,24 @@ WebStorageSessionStore.prototype = {
     },
 
     /**
-     * Stores the known devices for a user.
-     * @param {string} userId The user's ID.
-     * @param {object} devices A map from device ID to keys for the device.
+     * Retrieves the known devices for all users.
+     * @return {object} A map from user ID to map of device ID to keys for the device.
      */
-    storeEndToEndDevicesForUser: function(userId, devices) {
-        setJsonItem(this.store, keyEndToEndDevicesForUser(userId), devices);
-    },
-
-    /**
-     * Retrieves the known devices for a user.
-     * @param {string} userId The user's ID.
-     * @return {object} A map from device ID to keys for the device.
-     */
-    getEndToEndDevicesForUser: function(userId) {
-        return getJsonItem(this.store, keyEndToEndDevicesForUser(userId));
-    },
-
-    storeEndToEndDeviceTrackingStatus: function(statusMap) {
-        setJsonItem(this.store, KEY_END_TO_END_DEVICE_LIST_TRACKING_STATUS, statusMap);
+    getAllEndToEndDevices: function() {
+        const prefix = keyEndToEndDevicesForUser('');
+        const devices = {};
+        for (let i = 0; i < store.length; ++i) {
+            const key = store.key(i);
+            const userId = key.substr(prefix.length);
+            if (key.startsWith(prefix)) devices[userId] = getJsonItem(this.store, key);
+        }
+        return devices;
     },
 
     getEndToEndDeviceTrackingStatus: function() {
         return getJsonItem(this.store, KEY_END_TO_END_DEVICE_LIST_TRACKING_STATUS);
     },
 
-    /**
-     * Store the sync token corresponding to the device list.
-     *
-     * This is used when starting the client, to get a list of the users who
-     * have changed their device list since the list time we were running.
-     *
-     * @param {String?} token
-     */
-    storeEndToEndDeviceSyncToken: function(token) {
-        setJsonItem(this.store, KEY_END_TO_END_DEVICE_SYNC_TOKEN, token);
-    },
-
     /**
      * Get the sync token corresponding to the device list.
      *
@@ -114,6 +95,15 @@ WebStorageSessionStore.prototype = {
         return getJsonItem(this.store, KEY_END_TO_END_DEVICE_SYNC_TOKEN);
     },
 
+    /**
+     * Removes all end to end device data from the store
+     */
+    removeEndToEndDeviceData: function() {
+        removeByPrefix(this.store, keyEndToEndDevicesForUser(''));
+        removeByPrefix(this.store, KEY_END_TO_END_DEVICE_LIST_TRACKING_STATUS);
+        removeByPrefix(this.store, KEY_END_TO_END_DEVICE_SYNC_TOKEN);
+    },
+
     /**
      * Retrieve the end-to-end sessions between the logged-in user and another
      * device.