diff --git a/app-sync.js b/app-sync.js
index 439f8cc..7e2e012 100644
--- a/app-sync.js
+++ b/app-sync.js
@@ -8,7 +8,7 @@ let errorMiddleware = require('./util/error-middleware');
 let config = require('./load-config');
 let { getAccountDb } = require('./account-db');
 
-let fullSync = require('./sync-full');
+let simpleSync = require('./sync-simple');
 
 let actual = require('@actual-app/api');
 let SyncPb = actual.internal.SyncProtoBuf;
@@ -121,22 +121,12 @@ app.post('/sync', async (req, res) => {
     return false;
   }
 
-  // TODO: We also provide a "simple" sync method which currently isn't
-  // used. This method just stores the messages locally and doesn't
-  // load the whole app at all. If we want to support end-to-end
-  // encryption, this method is required because we can't read the
-  // messages. Using it looks like this:
-  //
-  // let simpleSync = require('./sync-simple');
-  // let {trie, newMessages } = simpleSync.sync(messages, since, file_id);
-
-  let { trie, newMessages } = await fullSync.sync(messages, since, file_id);
+  let { trie, newMessages } = simpleSync.sync(messages, since, group_id);
 
   // encode it back...
   let responsePb = new SyncPb.SyncResponse();
   responsePb.setMerkle(JSON.stringify(trie));
-
-  newMessages.forEach((msg) => responsePb.addMessages(msg));
+  newMessages.forEach(msg => responsePb.addMessages(msg));
 
   res.set('Content-Type', 'application/actual-sync');
   res.send(Buffer.from(responsePb.serializeBinary()));
@@ -306,6 +296,7 @@ app.post('/upload-user-file', async (req, res) => {
       'UPDATE files SET sync_version = ?, encrypt_meta = ?, name = ? WHERE id = ?',
       [syncFormatVersion, encryptMeta, name, fileId]
     );
+
     res.send(JSON.stringify({ status: 'ok', groupId }));
   }
 });
@@ -377,7 +368,7 @@ app.get('/list-user-files', (req, res) => {
   res.send(
     JSON.stringify({
       status: 'ok',
-      data: rows.map((row) => ({
+      data: rows.map(row => ({
         deleted: row.deleted,
         fileId: row.id,
         groupId: row.group_id,
diff --git a/sql/messages.sql b/sql/messages.sql
index 0c9ed77..64d35cb 100644
--- a/sql/messages.sql
+++ b/sql/messages.sql
@@ -1,10 +1,9 @@
 
 CREATE TABLE messages_binary
-  (timestamp TEXT,
+  (timestamp TEXT PRIMARY KEY,
    is_encrypted BOOLEAN,
-   content bytea,
-   PRIMARY KEY(timestamp, group_id));
+   content bytea);
 
 CREATE TABLE messages_merkles
-  (id TEXT PRIMAREY KEY,
+  (id INTEGER PRIMARY KEY,
    merkle TEXT);
diff --git a/sync-simple.js b/sync-simple.js
index d33ed39..e76e328 100644
--- a/sync-simple.js
+++ b/sync-simple.js
@@ -4,7 +4,8 @@ let { openDatabase } = require('./db');
 
 let actual = require('@actual-app/api');
 let merkle = actual.internal.merkle;
-let Timestamp = actual.internal.timestamp.Timestamp;
+let SyncPb = actual.internal.SyncProtoBuf;
+let Timestamp = actual.internal.timestamp.default;
 
 function getGroupDb(groupId) {
   let path = join(__dirname, `user-files/${groupId}.sqlite`);
@@ -57,7 +58,7 @@ function addMessages(db, messages) {
 }
 
 function getMerkle(db, group_id) {
-  let rows = db.all('SELECT * FROM messages_merkles', [group_id]);
+  let rows = db.all('SELECT * FROM messages_merkles');
 
   if (rows.length > 0) {
     return JSON.parse(rows[0].merkle);
@@ -68,8 +69,8 @@ function getMerkle(db, group_id) {
   }
 }
 
-function sync(messages, since, fileId) {
-  let db = getGroupDb(fileId);
+function sync(messages, since, groupId) {
+  let db = getGroupDb(groupId);
   let newMessages = db.all(
     `SELECT * FROM messages_binary
          WHERE timestamp > ?
@@ -79,7 +80,18 @@ function sync(messages, since, fileId) {
 
   let trie = addMessages(db, messages);
 
-  return { trie, newMessages };
+  db.close();
+
+  return {
+    trie,
+    newMessages: newMessages.map(msg => {
+      const envelopePb = new SyncPb.MessageEnvelope();
+      envelopePb.setTimestamp(msg.timestamp);
+      envelopePb.setIsencrypted(msg.is_encrypted);
+      envelopePb.setContent(msg.content);
+      return envelopePb;
+    })
+  };
 }
 
 module.exports = { sync };