diff --git a/core/tabularbulkexport.class.inc.php b/core/tabularbulkexport.class.inc.php
index c98283f61c..a755e85a33 100644
--- a/core/tabularbulkexport.class.inc.php
+++ b/core/tabularbulkexport.class.inc.php
@@ -8,9 +8,13 @@
 use Combodo\iTop\Application\UI\Base\Component\Input\InputUIBlockFactory;
 use Combodo\iTop\Application\UI\Base\Layout\UIContentBlockUIBlockFactory;
 use Combodo\iTop\Application\WebPage\WebPage;
+use Combodo\iTop\Core\AttributeDefinition\AttributeExternalField;
 use Combodo\iTop\Core\AttributeDefinition\AttributeExternalKey;
+use Combodo\iTop\Core\AttributeDefinition\AttributeFriendlyName;
 use Combodo\iTop\Core\AttributeDefinition\AttributeHierarchicalKey;
+use Combodo\iTop\Core\AttributeDefinition\AttributeLinkedSet;
 use Combodo\iTop\Core\AttributeDefinition\AttributeStopWatch;
+use Combodo\iTop\Core\AttributeDefinition\AttributeSubItem;
 
 /**
  * Bulk export: Tabular export: abstract base class for all "tabular" exports.