diff --git a/core/event.class.inc.php b/core/event.class.inc.php
index 52a51bbcd..3f58f38f9 100644
--- a/core/event.class.inc.php
+++ b/core/event.class.inc.php
@@ -340,9 +340,16 @@ class EventLoginUsage extends Event
 		MetaModel::Init_InheritAttributes();
 
 		MetaModel::Init_AddAttribute(new AttributeExternalKey("user_id", array("targetclass"=>"User", "jointype"=> "", "allowed_values"=>null, "sql"=>"user_id", "is_null_allowed"=>false, "on_target_delete"=>DEL_MANUAL, "depends_on"=>array())));
-		MetaModel::Init_AddAttribute(new AttributeExternalField("contact_name", array("allowed_values"=>null, "extkey_attcode"=>"user_id", "target_attcode"=>"contactid", "is_null_allowed"=>true, "depends_on"=>array())));
-		MetaModel::Init_AddAttribute(new AttributeExternalField("contact_email", array("allowed_values"=>null, "extkey_attcode"=>"user_id", "target_attcode"=>"email", "is_null_allowed"=>true, "depends_on"=>array())));
-
+		if (MetaModel::IsValidAttCode('Contact', 'name'))
+		{
+			MetaModel::Init_AddAttribute(new AttributeExternalField("contact_name", array("allowed_values"=>null, "extkey_attcode"=>"user_id", "target_attcode"=>"contactid", "is_null_allowed"=>true, "depends_on"=>array())));
+			$aZList[] = 'contact_name';
+		}
+		if (MetaModel::IsValidAttCode('Contact', 'email'))
+		{
+			MetaModel::Init_AddAttribute(new AttributeExternalField("contact_email", array("allowed_values"=>null, "extkey_attcode"=>"user_id", "target_attcode"=>"email", "is_null_allowed"=>true, "depends_on"=>array())));
+			$aZList[] = 'contact_email';
+		}
 		// Display lists
 		MetaModel::Init_SetZListItems('details', array('date', 'user_id', 'contact_name', 'contact_email', 'userinfo', 'message')); // Attributes to be displayed for the complete details
 		MetaModel::Init_SetZListItems('list', array('date', 'user_id', 'contact_name', 'contact_email', 'userinfo')); // Attributes to be displayed for a list