Div not echoing in wordpress php

Div not echoing in wordpress php

<?php
if ( is_user_logged_in() ) {
echo '<div id="signin-box"> '.wp_login_form().' </div>';
} else {
echo 'hi';
}
?>
Is what I've got. The login form is working, but it is not being wrapped
in the div. Without the else/if statement, it works.