<?php
    add_filter( 'pre_get_posts', 'add_to_query' );

    function add_to_query( $query ) {
        // if ( is_home() ) {
            if( $query->query_vars['suppress_filters'] ) // TODO check if necessary
                return $query;
            $supported = $query->get( 'post_type' );
            if ( !$supported || $supported == 'post' )
                $supported = array( 'post', 'paste' );
            elseif ( is_array( $supported ) )
                array_push( $supported, 'paste' );
            $query->set( 'post_type', $supported );
            return $query;
        //}
    }
?>