diff --git a/src/bootstrap/html_purifier.php b/src/bootstrap/html_purifier.php
index 582c635..d15f819 100644
--- a/src/bootstrap/html_purifier.php
+++ b/src/bootstrap/html_purifier.php
@@ -2,6 +2,8 @@
 
 declare(strict_types=1);
 
+namespace tts;
+
 if (!defined('HTMLPURIFIER_PREFIX')) {
   define('HTMLPURIFIER_PREFIX', TTS_VENDOR . 'ezyang/htmlpurifier/library');
 }
@@ -14,7 +16,7 @@ class HTMLPurifier_Bootstrap {
      * @return bool
      */
     public static function autoload($class) {
-        $file = HTMLPurifier_Bootstrap::getPath($class);
+        $file = \tts\HTMLPurifier_Bootstrap::getPath($class);
         if (!$file) {
             return false;
         }
@@ -53,7 +55,7 @@ class HTMLPurifier_Bootstrap {
      * "Pre-registers" our autoloader on the SPL stack.
      */
     public static function registerAutoload() {
-        $autoload = array('HTMLPurifier_Bootstrap', 'autoload');
+        $autoload = array('\tts\HTMLPurifier_Bootstrap', 'autoload');
         if (($funcs = spl_autoload_functions()) === false) {
             spl_autoload_register($autoload);
         } elseif (function_exists('spl_autoload_unregister')) {
diff --git a/src/classes/services/html_filter.php b/src/classes/services/html_filter.php
index 0f955f6..e7ada1d 100644
--- a/src/classes/services/html_filter.php
+++ b/src/classes/services/html_filter.php
@@ -10,7 +10,7 @@ final class html_filter {
 
   public function __construct() {
     if (\main_tts\registry::get('html_filter') === null) {
-      \HTMLPurifier_Bootstrap::registerAutoload();
+      \tts\HTMLPurifier_Bootstrap::registerAutoload();
       if (function_exists('__autoload')) {
           // Be polite and ensure that userland autoload gets retained
           spl_autoload_register('__autoload');