diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9901b8b..5de73a5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [Unreleased]
+
+### Fixed
+
+- Fix undefined `$CFG_GLPI` in `front/config.form.php` (PHP warnings and wrong redirect when GLPI is installed in a subdirectory)
+
 ## [1.5.0] - 2026-10-06
 
 ### Added
diff --git a/front/config.form.php b/front/config.form.php
index 14625c7..6fe899d 100644
--- a/front/config.form.php
+++ b/front/config.form.php
@@ -48,5 +48,6 @@
 } else {
     Session::checkRight(Config::$rightname, READ);
     /** @var array $CFG_GLPI */
+    global $CFG_GLPI;
     Html::redirect($CFG_GLPI['root_doc'] . '/front/config.form.php?forcetab=PluginMetabaseConfig$1');
 }