diff --git a/src/timemanagerapp/lib/database/MyDatebase.dart b/src/timemanagerapp/lib/database/MyDatebase.dart
index c0ab4ea..2f0c93f 100644
--- a/src/timemanagerapp/lib/database/MyDatebase.dart
+++ b/src/timemanagerapp/lib/database/MyDatebase.dart
@@ -48,7 +48,7 @@ class MyDatabase {
     await db.execute('''
       CREATE TABLE IF NOT EXISTS users(
           id BIGINT PRIMARY KEY,
-          username TEXT NOT NULL,
+          username VARCHAR(255) NOT NULL UNIQUE,
           password TEXT NOT NULL,
           role BIGINT NOT NULL
       );
@@ -112,7 +112,7 @@ class MyDatabase {
     await db.execute('''
       CREATE TABLE IF NOT EXISTS users(
           id BIGINT PRIMARY KEY,
-          username TEXT NOT NULL,
+          username VARCHAR(255) NOT NULL,
           password TEXT NOT NULL,
           role BIGINT NOT NULL
       );