diff --git a/spec/test-utils.js b/spec/test-utils.js
index ab47a85e7..88168130d 100644
--- a/spec/test-utils.js
+++ b/spec/test-utils.js
@@ -13,9 +13,14 @@ const MatrixEvent = sdk.MatrixEvent;
  */
 module.exports.syncPromise = function(client) {
     const def = q.defer();
-    client.on('sync', (state) => {
-        if (state == 'SYNCING') def.resolve();
-    });
+    const cb = (state) => {
+        if (state == 'SYNCING') {
+            def.resolve();
+        } else {
+            client.once('sync', cb);
+        }
+    };
+    client.once('sync', cb);
     return def.promise;
 };
 
diff --git a/src/indexeddb-worker.js b/src/indexeddb-worker.js
new file mode 100644
index 000000000..aa6312e2f
--- /dev/null
+++ b/src/indexeddb-worker.js
@@ -0,0 +1,24 @@
+/*
+Copyright 2017 Vector Creations Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/**
+ * Separate exports file for the indexeddb web worker, which is designed
+ * to be used separately
+ */
+
+/** The {@link module:indexeddb-store-worker~IndexedDBStoreWorker} class. */
+module.exports.IndexedDBStoreWorker = require("./store/indexeddb-store-worker.js");
+
diff --git a/src/matrix.js b/src/matrix.js
index 7ad894351..ea885b932 100644
--- a/src/matrix.js
+++ b/src/matrix.js
@@ -61,8 +61,6 @@ module.exports.Filter = require("./filter");
 module.exports.TimelineWindow = require("./timeline-window").TimelineWindow;
 /** The {@link module:interactive-auth} class. */
 module.exports.InteractiveAuth = require("./interactive-auth");
-/** The {@link module:indexeddb-remote-worker} class. */
-module.exports.IndexedDbStoreWorker = require("./store/indexeddb-remote-worker.js");
 
 
 /**
diff --git a/src/store/indexeddb-local-backend.js b/src/store/indexeddb-local-backend.js
index d0094e89b..0f4010d3c 100644
--- a/src/store/indexeddb-local-backend.js
+++ b/src/store/indexeddb-local-backend.js
@@ -243,7 +243,7 @@ LocalIndexedDBStoreBackend.prototype = {
     /**
      * Persist a list of [user id, presence event] they are for.
      * Users with the same 'userId' will be replaced.
-     * Prfesence events should be the event in its raw form (not the Event
+     * Presence events should be the event in its raw form (not the Event
      * object)
      * @param {Object[]} tuples An array of [userid, event] tuples
      * @return {Promise} Resolves if the users were persisted.
diff --git a/src/store/indexeddb-remote-backend.js b/src/store/indexeddb-remote-backend.js
index 6b27b9882..4daa60814 100644
--- a/src/store/indexeddb-remote-backend.js
+++ b/src/store/indexeddb-remote-backend.js
@@ -30,6 +30,7 @@ import q from "q";
 const RemoteIndexedDBStoreBackend = function RemoteIndexedDBStoreBackend(
     workerScript, dbName,
 ) {
+    this._dbName = dbName;
     this._worker = new Worker(workerScript);
     this._nextSeq = 0;
     // The currently in-flight requests to the actual backend
@@ -38,10 +39,6 @@ const RemoteIndexedDBStoreBackend = function RemoteIndexedDBStoreBackend(
     };
 
     this._worker.onmessage = this._onWorkerMessage.bind(this);
-
-    this._doCmd('_setupWorker', [dbName]).done(() => {
-        console.log("IndexedDB worker is ready");
-    });
 };
 
 
@@ -52,7 +49,10 @@ RemoteIndexedDBStoreBackend.prototype = {
      * @return {Promise} Resolves if successfully connected.
      */
     connect: function() {
-        return this._doCmd('connect');
+        return this._doCmd('_setupWorker', [this._dbName]).then(() => {
+            console.log("IndexedDB worker is ready");
+            return this._doCmd('connect');
+        });
     },
 
     /**
diff --git a/src/store/indexeddb-remote-worker.js b/src/store/indexeddb-store-worker.js
similarity index 69%
rename from src/store/indexeddb-remote-worker.js
rename to src/store/indexeddb-store-worker.js
index 0a857f0a9..725c6c91b 100644
--- a/src/store/indexeddb-remote-worker.js
+++ b/src/store/indexeddb-store-worker.js
@@ -18,10 +18,25 @@ import q from "q";
 import LocalIndexedDBStoreBackend from "./indexeddb-local-backend.js";
 
 /**
- * This class lives in the webworker and drives a LocalIndexedDbStoreBackend
+ * This class lives in the webworker and drives a LocalIndexedDBStoreBackend
  * controlled by messages from the main process.
+ *
+ * It should be instantiated by a web worker script provided by the application
+ * in a script, for example:
+ *
+ * import {IndexedDBStoreWorker} from 'matrix-js-sdk/lib/indexeddb-worker.js';
+ * const remoteWorker = new IndexedDBStoreWorker(postMessage);
+ * onmessage = remoteWorker.onMessage;
+ *
+ * Note that it is advisable to import this class by referencing the file directly to
+ * avoid a dependency on the whole js-sdk.
+ *
  */
-class IndexedDbStoreWorker {
+class IndexedDBStoreWorker {
+    /**
+     * @param {function} postMessage The web worker postMessage function that
+     * should be used to communicate back to the main script.
+     */
     constructor(postMessage) {
         this.backend = null;
         this.postMessage = postMessage;
@@ -29,6 +44,12 @@ class IndexedDbStoreWorker {
         this.onMessage = this.onMessage.bind(this);
     }
 
+    /**
+     * Passes a message event from the main script into the class. This method
+     * can be directly assigned to the web worker `onmessage` variable.
+     *
+     * @param {Object} ev The message event
+     */
     onMessage(ev) {
         const msg = ev.data;
         let prom;
@@ -51,7 +72,7 @@ class IndexedDbStoreWorker {
             case 'clearDatabase':
                 prom = this.backend.clearDatabase().then((result) => {
                     // This returns special classes which can't be cloned
-                    // accross to the main script, so don't try.
+                    // across to the main script, so don't try.
                     return {};
                 });
                 break;
@@ -76,7 +97,7 @@ class IndexedDbStoreWorker {
             postMessage({
                 command: 'cmd_fail',
                 seq: msg.seq,
-                // Canb't be an Error because they're not structured cloneable
+                // Can't be an Error because they're not structured cloneable
                 error: "Unrecognised command",
             });
             return;
@@ -89,13 +110,16 @@ class IndexedDbStoreWorker {
                 result: ret,
             });
         }, (err) => {
+            console.error("Error running command: "+msg.command);
+            console.error(err);
             this.postMessage.call(null, {
                 command: 'cmd_fail',
                 seq: msg.seq,
-                error: err,
+                // Just send a string because Error objects aren't cloneable
+                error: "Error running command",
             });
         });
     }
 }
 
-module.exports = IndexedDbStoreWorker;
+module.exports = IndexedDBStoreWorker;
diff --git a/src/store/indexeddb.js b/src/store/indexeddb.js
index 510b8fa63..50f816426 100644
--- a/src/store/indexeddb.js
+++ b/src/store/indexeddb.js
@@ -67,7 +67,7 @@ const WRITE_DELAY_MS = 1000 * 60 * 5; // once every 5 minutes
  * <code>window.indexedDB</code>
  * @param {string=} opts.dbName Optional database name. The same name must be used
  * to open the same database.
- * @param {string=} opts.workerScript Optional URL to a script to invooke a web
+ * @param {string=} opts.workerScript Optional URL to a script to invoke a web
  * worker with to run IndexedDB queries on the web worker. The IndexedDbStoreWorker
  * class is provided for this purpose and requires the application to provide a
  * trivial wrapper script around it.