Parse error - Comparing int values in a if statement

Currently I'm working on a function that should change the pos values (int values) of an array like this one:

$comb = array(
    'A' => array('pos' => 3, 'lett' => 'C'),
    'B' => array('pos' => 4, 'lett' => 'D'),
    );

The function that should perform what i need is the following one:

function change($comb) {
    foreach ($comb as $value) {
        if($value['pos']== 1) {
            $value['pos'] = 4;
        } else {
            $value['pos']--;
        }
    }
}

I can not understand why during the execution of the code, an general parse error occurs at the line of the if condition. I tried casting $value ['pos'] in int, but this does not seem to solve the problem.

Any idea?