diff --git a/packages/local-sync/src/local-api/routes/categories.js b/packages/local-sync/src/local-api/routes/categories.js
index 7b62141f8..c1e97de3a 100644
--- a/packages/local-sync/src/local-api/routes/categories.js
+++ b/packages/local-sync/src/local-api/routes/categories.js
@@ -72,7 +72,7 @@ module.exports = (server) => {
         tags: [term],
         validate: {
           params: {
-            id: Joi.number().integer(),
+            id: Joi.string(),
           },
         },
         response: {
diff --git a/packages/local-sync/src/local-api/serialization.js b/packages/local-sync/src/local-api/serialization.js
index 07527b1f6..4d585d0ae 100644
--- a/packages/local-sync/src/local-api/serialization.js
+++ b/packages/local-sync/src/local-api/serialization.js
@@ -35,7 +35,7 @@ function jsonSchema(modelName) {
   }
   if (modelName === 'Folder') {
     return Joi.object().keys({
-      id: Joi.number(),
+      id: Joi.string(),
       object: Joi.string(),
       account_id: Joi.string(),
       name: Joi.string().allow(null),
@@ -44,7 +44,7 @@ function jsonSchema(modelName) {
   }
   if (modelName === 'Label') {
     return Joi.object().keys({
-      id: Joi.number(),
+      id: Joi.string(),
       object: Joi.string(),
       account_id: Joi.string(),
       name: Joi.string().allow(null),
diff --git a/packages/local-sync/src/local-sync-worker/imap/fetch-folder-list.js b/packages/local-sync/src/local-sync-worker/imap/fetch-folder-list.js
index 0b95dadf2..e3d848408 100644
--- a/packages/local-sync/src/local-sync-worker/imap/fetch-folder-list.js
+++ b/packages/local-sync/src/local-sync-worker/imap/fetch-folder-list.js
@@ -1,3 +1,4 @@
+const crypto = require('crypto')
 const {Provider, PromiseUtils} = require('isomorphic-core');
 const {localizedCategoryNames} = require('../sync-utils')
 
@@ -93,6 +94,7 @@ class FetchFolderList {
         const role = this._roleByAttr(box);
         const Klass = this._classForMailboxWithRole(role, this._db);
         category = Klass.build({
+          id: crypto.createHash('sha256').update(boxName, 'utf8').digest('hex'),
           name: boxName,
           accountId: this._db.accountId,
           role: role,
diff --git a/packages/local-sync/src/models/folder.js b/packages/local-sync/src/models/folder.js
index 5d8d2fe12..769f513b9 100644
--- a/packages/local-sync/src/models/folder.js
+++ b/packages/local-sync/src/models/folder.js
@@ -2,6 +2,7 @@ const {DatabaseTypes: {JSONType}} = require('isomorphic-core');
 
 module.exports = (sequelize, Sequelize) => {
   return sequelize.define('folder', {
+    id: { type: Sequelize.STRING(65), primaryKey: true },
     accountId: { type: Sequelize.STRING, allowNull: false },
     version: Sequelize.INTEGER,
     name: Sequelize.STRING,
diff --git a/packages/local-sync/src/models/label.js b/packages/local-sync/src/models/label.js
index e6e64b735..8c9a67ba1 100644
--- a/packages/local-sync/src/models/label.js
+++ b/packages/local-sync/src/models/label.js
@@ -1,5 +1,6 @@
 module.exports = (sequelize, Sequelize) => {
   return sequelize.define('label', {
+    id: { type: Sequelize.STRING(65), primaryKey: true },
     accountId: { type: Sequelize.STRING, allowNull: false },
     version: Sequelize.INTEGER,
     name: Sequelize.STRING,