Try Rector Online | Rector - Automated Way to Instantly Upgrade and Refactor any PHP code

Run Rector on your code to see what it can do for you:

 interface Foo {}
 interface Bar {}
 
-function name(Foo&Bar $foo = null): string {
+function name((Foo&Bar)|null $foo = null): string {
     return (string) $foo;
 }

PHP snippet to change

<?php

interface Foo {}
interface Bar {}

function name(Foo&Bar $foo = null): string {
    return (string) $foo;
}

Applied Rules:

ExplicitNullableParamTypeRector

Not a change you expect?

Create an issue on GitHub
...or to speed up fix – add a test fixture

Config rector.php

<?php

use Rector\Config\RectorConfig;
use Rector\ValueObject\PhpVersion;

return RectorConfig::configure()
    ->withPhpSets(php85: true);

Rector version: 0594c1 - released at 2026-05-08 19:57