HHVM Constructor arg promotion

$ cat hh.php 
<?hh class Foo { public function __construct(private int $num) : void { } }

$ hhvm --version
HipHop VM 2.4.0 (rel)
Compiler: tags/HHVM-2.4.0-0-gc82fcd8e6199c500454b1a8b930a876ef2c1522b
Repo schema: a536a1d1567b1fb5d722c0349a3296d4e8589f96

$ hhvm hh.php 
HipHop Fatal error: Parameters modifiers not allowed on methods in /home/base/hh.php on line 1

Change it to:

<?hh class Foo { public function __construct(private int $num) : void { } }

Fixed :-)