Try adding this to your functions.php.
function my_custom_get_posts( $query ) {
if ( is_admin() || ! $query->is_main_query() )
return;
if ( $query->is_search ) {
$query->set( 'post_type', array( 'post', 'movie' ) );
}
}
add_action( 'pre_get_posts', 'my_custom_get_posts', 1 );
Also make sure you do not have any other pre_get_posts
action overwriting this function's effect.