diff --git a/backend/models/User.js b/backend/models/User.js
index 6ac87b6..7a148fe 100644
--- a/backend/models/User.js
+++ b/backend/models/User.js
@@ -4,7 +4,11 @@ const { Schema } = mongoose;
 // Schemas
 const UserSchema = new Schema({
   id: { type: String, required: true },
-  role: { type: String, required: true },
+  role: {
+    type: String,
+    required: true,
+    enum: ['admin', 'guest', 'user', 'vk'],
+  },
   token: { type: String, required: true },
 });
 
diff --git a/backend/routes/auth/guest.js b/backend/routes/auth/guest.js
index eb1f418..ba8c54a 100644
--- a/backend/routes/auth/guest.js
+++ b/backend/routes/auth/guest.js
@@ -21,7 +21,14 @@ const generateUser = id => {
 const saveUser = user => {
   const model = new User({ ...user });
 
-  return model.save();
+  return model.save()
+    .then(() => model.toObject())
+    .catch(() => ({
+      ...user,
+      success: false,
+      error: 'Error saving user model',
+      error_code: 1232,
+    }));
 };
 
 const generateRandomUrl = () => Promise.resolve(genRandomSequence(16));
@@ -35,10 +42,9 @@ const generateGuest = async () => {
 };
 
 module.exports = async (req, res) => {
-  const user = await generateGuest();
-  await saveUser(user);
+  const user = await generateGuest().then(saveUser);
 
-  res.send({ success: 'true', ...user });
+  res.send({ success: true, ...user });
 };
 
 module.exports.generateGuest = generateGuest;