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:

 <?php
 
 interface FooInterface {}

 
 class Imp implements DoX
 {
-	public function run(): A|B
+	/**
+     * @return \A|\B
+     */
+    public function run()
     {
     	return new A();
     }
 }

PHP snippet to change

<?php

interface FooInterface {}
class A implements FooInterface {}
class B implements FooInterface {}

interface DoX 
{
	public function run(): FooInterface;
}

class Imp implements DoX
{
	public function run(): A|B
    {
    	return new A();
    }
}

Applied Rules:

DowngradeUnionTypeDeclarationRector

Not a change you expect?

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

Config rector.php

<?php

declare(strict_types=1);

use Rector\Config\RectorConfig;

return RectorConfig::configure()
    ->withDowngradeSets(php74: true);

Rector version: b855ff - released at 2026-01-22 19:37