diff --git a/libraries/classes/ThemeManager.php b/libraries/classes/ThemeManager.php
index 186701e5de8a..62e7764e801f 100644
--- a/libraries/classes/ThemeManager.php
+++ b/libraries/classes/ThemeManager.php
@@ -228,7 +228,7 @@ public function setThemeCookie(): bool
     public function loadThemes(): void
     {
         $this->themes = [];
-        $dirHandle = opendir(ROOT_PATH . 'themes/');
+        $dirHandle = opendir($this->themesPath);
 
         if ($dirHandle === false) {
             trigger_error('Error: cannot open themes folder: ./themes', E_USER_WARNING);