diff --git a/src/store/indexeddb.js b/src/store/indexeddb.js
index 8fa102eac..30faf40ce 100644
--- a/src/store/indexeddb.js
+++ b/src/store/indexeddb.js
@@ -284,19 +284,15 @@ IndexedDBStore.prototype.getSyncAccumulator = function() {
 };
 
 /**
- * Set a new sync token and possibly write to the database.
- * Overrides MatrixInMemoryStore.
- * @param {string} token The new sync token
- * @return {?Promise} A promise if this sync token triggered a write to the
- * database, else null. Promise resolves after the write completes.
+ * Possibly write data to the database.
+ * @return {Promise} Promise resolves after the write completes.
  */
-IndexedDBStore.prototype.setSyncToken = function(token) {
-    MatrixInMemoryStore.prototype.setSyncToken.call(this, token);
+IndexedDBStore.prototype.save = function() {
     const now = Date.now();
     if (now - this._syncTs > WRITE_DELAY_MS) {
         return this._syncToDatabase().catch((err) => {console.error("sync fail:", err);});
     }
-    return null;
+    return q();
 };
 
 IndexedDBStore.prototype._setSyncData = function(nextBatch, roomsData) {
diff --git a/src/store/memory.js b/src/store/memory.js
index cf52f8074..b14b25f7d 100644
--- a/src/store/memory.js
+++ b/src/store/memory.js
@@ -274,4 +274,9 @@ module.exports.MatrixInMemoryStore.prototype = {
     getAccountData: function(eventType) {
         return this.accountData[eventType];
     },
+
+    /**
+     * Save does nothing as there is no backing data store.
+     */
+    save: function() {},
 };
diff --git a/src/store/stub.js b/src/store/stub.js
index ad5e3580c..ed9da2ef3 100644
--- a/src/store/stub.js
+++ b/src/store/stub.js
@@ -179,6 +179,11 @@ StubStore.prototype = {
     getAccountData: function(eventType) {
 
     },
+
+    /**
+     * Save does nothing as there is no backing data store.
+     */
+    save: function() {},
 };
 
 /** Stub Store class. */
diff --git a/src/sync.js b/src/sync.js
index 8931ec92e..c8d0ace77 100644
--- a/src/sync.js
+++ b/src/sync.js
@@ -570,6 +570,10 @@ SyncApi.prototype._sync = function(syncOptions) {
         // keep emitting SYNCING -> SYNCING for clients who want to do bulk updates
         self._updateSyncState("SYNCING", syncEventData);
 
+        // tell databases that everything is now in a consistent state and can be
+        // saved.
+        client.store.save();
+
         self._sync(syncOptions);
     }, function(err) {
         if (!self._running) {