selfOut.internalInterface

Code example

<?php declare(strict_types = 1);

namespace Vendor {
	/** @internal */
	interface InternalInterface {}
}

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

Why is it reported?

The @phpstan-self-out PHPDoc tag references an interface that is marked as @internal. Internal interfaces are not part of the public API of their package and may change or be removed without notice. Using internal types in @phpstan-self-out annotations creates a fragile dependency on implementation details.

How to fix it

Use a public (non-internal) interface in the @phpstan-self-out tag:

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

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