Repository navigation
Class that uses a trait is not found when instantiated before its declaration #24519
Description
Description
This is the same report as bugs.php.net #75771, which is still open.
The following code:
<?php
new A; // good.
new B; // fatal error.
class A {
function __construct() {
echo "constructed A\n";
}
}
class B {
use T;
function __construct() {
echo "constructed B\n";
$this->traitfunc();
}
}
new B; // good.
trait T {
function traitfunc() {
echo "traitfunc called\n";
}
}Resulted in this output:
constructed A
Fatal error: Uncaught Error: Class "B" not found in /mnt/c/Users/sybre/AppData/Local/Temp/bug75771.php:3
Stack trace:
#0 {main}
thrown in /mnt/c/Users/sybre/AppData/Local/Temp/bug75771.php on line 3
But I expected this output instead:
constructed A
constructed B
traitfunc called
PHP Version
PHP 8.5.12 (cli) (built: Oct 21 2026 22:48:15) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.5.12, Copyright (c) Zend Technologies
with Zend OPcache v8.5.12, Copyright (c), by Zend Technologies
Operating System
Ubuntu 24.04 (WSL2). Also reproduced on PHP 8.4.4 on Windows.
Activity
NickSdot commentedon Oct 23, 2026
Not a bug, intentional limitation. Applies to interface- and trait-using classes. Same category as this and this, which are
WONTFIX. Source ref: here and here.More context:
https://www.npopov.com/2021/10/20/Early-binding-in-PHP.html
Perhaps worth to document this better. Maybe you want to consider closing this issue.