find out how to change h1 entry title with h2 in class pages solely

That is the perform im utilizing:

perform change_title_h1_h2( $title, $id = null ) {

    return '<h2>'.$title.'</h2>';
}
add_filter( 'the_title', 'change_title_h1_h2', 10, 2 );

Is there any technique to simply goal the title of the posts within the class pages?

thx!