Menu

← Back to class.*

Error Identifier: class.duplicateConstant

Every error reported by PHPStan has an error identifier. Here’s a list of all error identifiers. In PHPStan Pro you can see the error identifier next to each error and filter errors by their identifiers.

Code example #

<?php declare(strict_types = 1);

class Foo
{
    public const BAR = 1;
    public const BAR = 2;
}

Why is it reported? #

The class declares the same constant name more than once. PHP does not allow redeclaring a class constant within the same class body. This will cause a fatal error at runtime.

How to fix it #

Remove the duplicate constant declaration, or rename one of the constants to avoid the conflict:

 <?php declare(strict_types = 1);
 
 class Foo
 {
     public const BAR = 1;
-    public const BAR = 2;
+    public const BAZ = 2;
 }

Non-ignorable error #

This error cannot be ignored using @phpstan-ignore or the ignoreErrors configuration. Non-ignorable errors indicate code that would cause a crash or a fatal error at runtime, or a fundamental problem in the analysed code that must be addressed.

Rules that report this error #

  • PHPStan\Rules\Classes\DuplicateDeclarationRule [1]

Edit this page on GitHub

Theme
A
© 2026 PHPStan s.r.o.