diff --git a/lib/Alchemy/Phrasea/SearchEngine/Elastic/Thesaurus/Helper.php b/lib/Alchemy/Phrasea/SearchEngine/Elastic/Thesaurus/Helper.php
index 21e0a4c39d..216a9faba7 100644
--- a/lib/Alchemy/Phrasea/SearchEngine/Elastic/Thesaurus/Helper.php
+++ b/lib/Alchemy/Phrasea/SearchEngine/Elastic/Thesaurus/Helper.php
@@ -41,7 +41,19 @@ class Helper
 
     public static function candidatesFromDatabox(databox $databox)
     {
-        return self::document($databox->get_dom_cterms());
+        $document = $databox->get_dom_cterms();
+        if (!$document) {
+            $document = new DOMDocument('1.0', 'UTF-8');
+            $document->xmlStandalone = true;
+            $document->formatOutput = true;
+            $element = $document->createElement('cterms');
+            $element->setAttribute('creation_date', date('YmdHis'));
+            $element->setAttribute('next_id', 0);
+            $element->setAttribute('version', '2.0.5');
+            $document->appendChild($element);
+        }
+
+        return $document;
     }
 
     private static function document($document)
diff --git a/lib/classes/databox.php b/lib/classes/databox.php
index 27afd31626..0a366e6d99 100644
--- a/lib/classes/databox.php
+++ b/lib/classes/databox.php
@@ -887,10 +887,6 @@ class databox extends base
 
     public function saveCterms(DOMDocument $dom_cterms)
     {
-        if (null === $dom_cterms->documentElement) {
-            $cterms = $dom_cterms->createElement('cterms');
-            $dom_cterms->appendChild($cterms);
-        }
         $dom_cterms->documentElement->setAttribute("modification_date", $now = date("YmdHis"));
 
         $sql = "UPDATE pref SET value = :xml, updated_on = :date