diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73bffd26..398e35bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [UNRELEASED]
 
+### Fixed
+
+- Internal server error when generating appliance asset pdf
+
 ## [4.1.5] - 2026-09-01
 
 ### Fixed
diff --git a/inc/appliance.class.php b/inc/appliance.class.php
index bbee4b13..62852ef8 100644
--- a/inc/appliance.class.php
+++ b/inc/appliance.class.php
@@ -219,7 +219,8 @@ public static function pdfForAppliance(PluginPdfSimplePDF $pdf, Appliance $appli
         $pdf->displayTitle('<b>' . _sn('Associated item', 'Associated items', 2) . '</b>');
 
         $result = $DB->request([
-            'SELECT' => 'DISTINCT itemtype',
+            'SELECT' => 'itemtype',
+            'DISTINCT' => true,
             'FROM'   => 'glpi_appliances_items',
             'WHERE'  => ['appliances_id' => $instID],
         ]);