diff --git a/app/code/Magento/ImportExport/Model/Export.php b/app/code/Magento/ImportExport/Model/Export.php
index 50a46201e064d..695df18fd1030 100644
--- a/app/code/Magento/ImportExport/Model/Export.php
+++ b/app/code/Magento/ImportExport/Model/Export.php
@@ -70,7 +70,7 @@ class Export extends \Magento\ImportExport\Model\AbstractModel
     /**
      * @var array
      */
-    protected static $backendTypeToFilterMapper = [
+    private static $backendTypeToFilterMapper = [
         'datetime' => self::FILTER_TYPE_DATE,
         'decimal' => self::FILTER_TYPE_NUMBER,
         'int' => self::FILTER_TYPE_NUMBER,