diff --git a/lib/job/arUpdatePublicationStatusJob.class.php b/lib/job/arUpdatePublicationStatusJob.class.php
index f3f524b4cc..fc13012741 100644
--- a/lib/job/arUpdatePublicationStatusJob.class.php
+++ b/lib/job/arUpdatePublicationStatusJob.class.php
@@ -78,7 +78,7 @@ public function runJob($parameters)
 
         $queryScript = \Elastica\Script\AbstractScript::create([
             'script' => [
-                'inline' => 'ctx._source.publicationStatusId = '.$publicationStatus->id,
+                'source' => 'ctx._source.publicationStatusId = '.$publicationStatus->id,
                 'lang' => 'painless',
             ],
         ]);
diff --git a/lib/task/tools/updatePublicationStatusTask.class.php b/lib/task/tools/updatePublicationStatusTask.class.php
index eee2a902eb..0c343826bc 100644
--- a/lib/task/tools/updatePublicationStatusTask.class.php
+++ b/lib/task/tools/updatePublicationStatusTask.class.php
@@ -166,7 +166,7 @@ protected function updatePublicationStatusDescendants($resource, $publicationSta
 
         $queryScript = \Elastica\Script\AbstractScript::create([
             'script' => [
-                'inline' => 'ctx._source.publicationStatusId = '.$publicationStatus->id,
+                'source' => 'ctx._source.publicationStatusId = '.$publicationStatus->id,
                 'lang' => 'painless',
             ],
         ]);
diff --git a/plugins/arElasticSearchPlugin/lib/arElasticSearchIndexDecorator.class.php b/plugins/arElasticSearchPlugin/lib/arElasticSearchIndexDecorator.class.php
deleted file mode 100644
index 02a45ec56e..0000000000
--- a/plugins/arElasticSearchPlugin/lib/arElasticSearchIndexDecorator.class.php
+++ /dev/null
@@ -1,83 +0,0 @@
-<?php
-
-/*
- * This file is part of the Access to Memory (AtoM) software.
- *
- * Access to Memory (AtoM) is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Access to Memory (AtoM) is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Access to Memory (AtoM).  If not, see <http://www.gnu.org/licenses/>.
- */
-
-use Elastica\Query;
-use Elastica\Response;
-use Elastica\Script\AbstractScript;
-use Elasticsearch\Endpoints\UpdateByQuery;
-
-/**
- * arElasticSearchIndexDecorator can be removed when Elastica >= 6.x. It is present to
- * provide Elastica/Index::updateByQuery().
- *
- * @author      sbreker <sbreker@artefactual.com>
- */
-class arElasticSearchIndexDecorator
-{
-    protected $_instance;
-
-    public function __construct(Elastica\Index $instance)
-    {
-        $this->_instance = $instance;
-    }
-
-    public function __call($method, $args)
-    {
-        return call_user_func_array([$this->_instance, $method], $args);
-    }
-
-    public function __get($key)
-    {
-        return $this->_instance->{$key};
-    }
-
-    public function __set($key, $val)
-    {
-        return $this->_instance->{$key} = $val;
-    }
-
-    public function getInstance()
-    {
-        return $this->_instance;
-    }
-
-    /**
-     * Update entries in the db based on a query.
-     *
-     * @param AbstractQuery|array|Collapse|Query|string|Suggest $query   Query object or array
-     * @param AbstractScript                                    $script  Script
-     * @param array                                             $options Optional params
-     *
-     * @see https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-update-by-query.html
-     */
-    public function updateByQuery($query, AbstractScript $script, array $options = []): Response
-    {
-        $endpoint = new UpdateByQuery();
-        $q = Query::create($query)->getQuery();
-        $body = [
-            'query' => \is_array($q) ? $q : $q->toArray(),
-            'script' => $script->toArray()['script'],
-        ];
-
-        $endpoint->setBody($body);
-        $endpoint->setParams($options);
-
-        return $this->requestEndpoint($endpoint);
-    }
-}
diff --git a/plugins/arElasticSearchPlugin/lib/arElasticSearchPlugin.class.php b/plugins/arElasticSearchPlugin/lib/arElasticSearchPlugin.class.php
index 07e9179900..2b804c2203 100644
--- a/plugins/arElasticSearchPlugin/lib/arElasticSearchPlugin.class.php
+++ b/plugins/arElasticSearchPlugin/lib/arElasticSearchPlugin.class.php
@@ -92,7 +92,7 @@ public function __construct(array $options = [])
 
         // TODO: arElasticSearchIndexDecorator can be removed when Elastica >= 6.x. It is present to
         // provide Elastica/Index::updateByQuery().
-        $this->index = new arElasticSearchIndexDecorator($this->client->getIndex($this->config['index']['name']));
+        $this->index = $this->client->getIndex($this->config['index']['name']);
 
         // Load batch mode configuration
         $this->batchMode = true === $this->config['batch_mode'];