diff --git a/handlers/messages/addUser.js b/handlers/messages/addUser.js
index ef8e063..07331fd 100644
--- a/handlers/messages/addUser.js
+++ b/handlers/messages/addUser.js
@@ -29,6 +29,7 @@ const addUserHandler = async (ctx, next) => {
 		isAdmin: user && user.status === 'admin',
 		isMaster: user &&
 			user.id === Number(master) ||
+			user.username &&
 			user.username.toLowerCase() ===
 				String(master).replace('@', '').toLowerCase(),
 		user: newUser,
diff --git a/handlers/middlewares/addedToGroup.js b/handlers/middlewares/addedToGroup.js
index a530c30..5a4a631 100644
--- a/handlers/middlewares/addedToGroup.js
+++ b/handlers/middlewares/addedToGroup.js
@@ -11,6 +11,7 @@ const addedToGroupHandler = async (ctx, next) => {
 	const msg = ctx.message;
 	const { telegram } = ctx;
 	const isMaster = ctx.from.id === Number(master) ||
+		ctx.from.username &&
 		ctx.from.username.toLowerCase() ===
 		String(master).replace('@', '').toLowerCase();