diff --git a/public/src/client/register.js b/public/src/client/register.js
index 62dbc41..fe13476 100644
--- a/public/src/client/register.js
+++ b/public/src/client/register.js
@@ -131,7 +131,9 @@ define('forum/register', [
                 if (results.every(obj => obj.status === 'rejected')) {
                     showSuccess(username_notify, successIcon);
                 } else {
-                    showError(username_notify, '[[error:username-taken]]');
+                    const newUsername = suggestUsername(username);
+                    showError(username_notify, '[[error:username-taken. maybe-try-${newUsername}]]');
+                    $('#username').val(newUsername);
                 }
 
                 callback();
@@ -139,6 +141,10 @@ define('forum/register', [
         }
     }
 
+    function suggestUsername(username) {
+        return username + 123;
+    }
+
     function validatePassword(password, password_confirm) {
         const password_notify = $('#password-notify');
         const password_confirm_notify = $('#password-confirm-notify');