Exclude posts from certain category

I have a separate page for posts of a certain category, so I don’t want to show posts from that category in the standard loop

So I have on my archive template

<?php query_posts('cat=-6'); ?>
			
<?php if (have_posts()) : ?>
            
<?php while (have_posts()) : the_post(); ?>
            
Blah blah
                    
<?php endwhile; ?>
    
<?php else : ?>
    
<h1>Oops</h1>
    
<?php endif; ?>

however this is still showing posts from category with ID 6.