diff --git a/src/OowpQuery.php b/src/OowpQuery.php
index 37a5aa5..a7d4ffd 100644
--- a/src/OowpQuery.php
+++ b/src/OowpQuery.php
@@ -29,11 +29,7 @@ function __construct($query = '')
         // 'attachment' which can cause crashes on ?preview=true if a file title matches a render-able post's.
         if (!isset($query['post_type']) || (!is_array($query['post_type']) && !array_key_exists($query['post_type'],
                     $wp_post_types))) {
-            $query['post_type'] = array_values(get_post_types());
-            $attachmentTypeIndex = array_search('attachment', $query['post_type'], true);
-            if ($attachmentTypeIndex !== false) {
-                array_splice($query['post_type'], $attachmentTypeIndex, 1);
-            }
+            $query['post_type'] = array_values(array_diff(get_post_types(), array('attachment')));
         }
 
         parent::__construct($query);