selfOut.internalClass

Code example

<?php declare(strict_types = 1);

namespace Vendor {
	/** @internal */
	class InternalType {}
}

namespace App {
	class Builder {
		/**
		 * @phpstan-self-out \Vendor\InternalType
		 */
		public function build(): void {}
	}
}

Why is it reported?

The @phpstan-self-out PHPDoc tag references a class that is marked as @internal. Internal classes are not part of the public API of their package and may change or be removed at any time. Referencing them in a @phpstan-self-out tag creates a dependency on an internal implementation detail that may break without notice.

How to fix it

Replace the internal class with a public type:

 class Builder {
 	/**
-	 * @phpstan-self-out \Vendor\InternalType
+	 * @phpstan-self-out \Vendor\PublicType
 	 */
 	public function build(): void {}
 }

If the class is internal to the same package, the error will not be reported. The @internal restriction only applies to cross-package usage.