diff --git a/bundles/AdminBundle/Resources/views/Admin/DataObject/DataObject/previewVersion.html.twig b/bundles/AdminBundle/Resources/views/Admin/DataObject/DataObject/previewVersion.html.twig
index 9b240bb0f4c..925d54512d3 100644
--- a/bundles/AdminBundle/Resources/views/Admin/DataObject/DataObject/previewVersion.html.twig
+++ b/bundles/AdminBundle/Resources/views/Admin/DataObject/DataObject/previewVersion.html.twig
@@ -111,7 +111,7 @@
             {% if activeGroups is not empty %}
                 {% set languages = ['default'] %}
                 {% if definition.isLocalized() %}
-                    {% set languages = validLanguages + languages %}
+                    {% set languages = validLanguages|merge(languages) %}
                 {% endif %}
 
                 {% for activeGroupId, enabled in activeGroups %}
@@ -133,7 +133,7 @@
                                     {% set preview = keyDef.getVersionPreview(keyData) %}
                                     <tr {% if loop.index is odd %}class="odd"{% endif %}>
                                         <td>{{ definition.getTitle()|trans([],'admin') }}</td>
-                                        <td>{{ groupDefinition.getName() ~ "-" ~ keyGroupRelation.getName() }} {{ definition.isLocalized() ? "/ " . language : ""  }}</td>
+                                        <td>{{ groupDefinition.getName() ~ "-" ~ keyGroupRelation.getName() }} {{ definition.isLocalized() ? "/ " ~ language : ""  }}</td>
                                         {% if isImportPreview is not defined or isNew is not defined %}
                                             <td>{{ preview | raw }}</td>
                                         {% endif %}