diff --git a/php/controller/showCategory-controller.php b/php/controller/showCategory-controller.php
index aee1114..1f20f34 100644
--- a/php/controller/showCategory-controller.php
+++ b/php/controller/showCategory-controller.php
@@ -5,6 +5,7 @@ if (session_status() === PHP_SESSION_NONE) {
 
 require_once 'php/model/Article.php';
 require_once 'php/model/ArticleManager.php';
+require_once 'php/model/UserManager.php';
 require_once 'php/validator/article-validator.php';
 
 if (isset($_GET["category"]) && !empty($_GET["category"]) && articleCategoryValidator($_GET["category"])){