Index: src/wp-includes/canonical.php
===================================================================
--- src/wp-includes/canonical.php	(revision 44723)
+++ src/wp-includes/canonical.php	(working copy)
@@ -664,8 +664,14 @@
 		$where = $wpdb->prepare( 'post_name LIKE %s', $wpdb->esc_like( get_query_var( 'name' ) ) . '%' );
 
 		// if any of post_type, year, monthnum, or day are set, use them to refine the query
-		if ( get_query_var( 'post_type' ) ) {
-			$where .= $wpdb->prepare( ' AND post_type = %s', get_query_var( 'post_type' ) );
+		$post_type = get_query_var( 'post_type' );
+
+		if ( $post_type ) {
+			if ( is_array( $post_type ) ) {
+				$where .= " AND post_type IN ('" . join( "', '", esc_sql( $post_type ) ) . "')";
+			} else {
+				$where .= $wpdb->prepare( ' AND post_type = %s', get_query_var( 'post_type' ) );
+			}
 		} else {
 			$where .= " AND post_type IN ('" . implode( "', '", get_post_types( array( 'public' => true ) ) ) . "')";
 		}