diff --git a/app/Http/Controllers/UsersController.php b/app/Http/Controllers/UsersController.php
index a57ecb0..949cbd6 100644
--- a/app/Http/Controllers/UsersController.php
+++ b/app/Http/Controllers/UsersController.php
@@ -60,7 +60,7 @@ class UsersController extends Controller
         $user = $request->user();
 
         $request->validate([
-            'username' => ['required', 'string', 'max:255'],
+            'username' => ['required', 'string','min:3', 'max:30', 'regex:/^[A-Za-z0-9._]+$/'],
         ]);
 
         $user->update([
diff --git a/app/Http/Requests/Auth/RegisterRequest.php b/app/Http/Requests/Auth/RegisterRequest.php
index 26cbb02..e62558c 100644
--- a/app/Http/Requests/Auth/RegisterRequest.php
+++ b/app/Http/Requests/Auth/RegisterRequest.php
@@ -24,7 +24,7 @@ class RegisterRequest extends FormRequest
     public function rules(): array
     {
         return [
-            'username' => ['required', 'string', 'max:120', 'unique:users,username'],
+            'username' => ['required', 'string','min:3', 'max:30', 'regex:/^[A-Za-z0-9._]+$/'],
             'email' => ['required', 'string', 'email', 'max:255', 'unique:users,email'],
             'password' => [
                 'required',