diff --git a/inc/targetchange.class.php b/inc/targetchange.class.php
index bef18161b..51b927e01 100644
--- a/inc/targetchange.class.php
+++ b/inc/targetchange.class.php
@@ -667,7 +667,7 @@ public function save(PluginFormcreatorFormAnswer $formanswer): ?CommonDBTM {
       ];
       foreach ($changeFields as $changeField) {
          $data[$changeField] = $this->prepareTemplate(
-            $this->fields[$changeField],
+            $this->fields[$changeField] ?? '',
             $formanswer,
             $changeField == 'content' // only content supports rich text
          );