diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/ConfigSchema.php b/htdocs/vendor/ezyang/htmlpurifier/library/HTMLPurifier/ConfigSchema.php
index c3fe8cd4ab..acb66fe41a 100644
--- a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/ConfigSchema.php
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/ConfigSchema.php
@@ -68,7 +68,7 @@ class HTMLPurifier_ConfigSchema
      */
     public static function makeFromSerial()
     {
-        $contents = file_get_contents(HTMLPURIFIER_PREFIX . '/HTMLPurifier/ConfigSchema/schema.ser');
+        $contents = file_get_contents(get_config('docroot') . 'lib/htmlpurifier/schema.ser');
         $r = unserialize($contents);
         if (!$r) {
             $hash = sha1($contents);