diff --git a/Application/Model/ExportRenderer/Pretty.php b/Application/Model/ExportRenderer/Pretty.php
index 8ae60d9..0ec7838 100644
--- a/Application/Model/ExportRenderer/Pretty.php
+++ b/Application/Model/ExportRenderer/Pretty.php
@@ -20,12 +20,12 @@ use MathieuViossat\Util\ArrayToTextTable;
 class Pretty implements RendererInterface
 {
     /**
-     * @param $rows
-     * @param $fieldNames
+     * @param iterable $rows
+     * @param iterable $fieldNames
      *
      * @return string
      */
-    public function getContent($rows, $fieldNames): string
+    public function getContent(iterable $rows, iterable $fieldNames): string
     {
         $renderer = $this->getArrayToTextTableInstance($rows);
         return $renderer->getTable();
diff --git a/Application/Model/ExportRenderer/RendererInterface.php b/Application/Model/ExportRenderer/RendererInterface.php
index 7b57496..37f8c71 100644
--- a/Application/Model/ExportRenderer/RendererInterface.php
+++ b/Application/Model/ExportRenderer/RendererInterface.php
@@ -18,12 +18,12 @@ namespace D3\DataWizard\Application\Model\ExportRenderer;
 interface RendererInterface
 {
     /**
-     * @param $rows
-     * @param $fieldNames
+     * @param iterable $rows
+     * @param iterable $fieldNames
      *
      * @return string
      */
-    public function getContent($rows, $fieldNames): string;
+    public function getContent(iterable $rows, iterable $fieldNames): string;
 
     /**
      * @return string
diff --git a/tests/unit/Application/Model/ExportBaseTest.php b/tests/unit/Application/Model/ExportBaseTest.php
index 603dbea..263fd5e 100644
--- a/tests/unit/Application/Model/ExportBaseTest.php
+++ b/tests/unit/Application/Model/ExportBaseTest.php
@@ -30,6 +30,7 @@ use FormManager\Inputs\Number;
 use FormManager\Inputs\Radio;
 use OxidEsales\Eshop\Core\Database\Adapter\Doctrine\Database;
 use OxidEsales\Eshop\Core\Exception\StandardException;
+use OxidEsales\Eshop\Core\Registry;
 use PHPUnit\Framework\MockObject\MockObject;
 use ReflectionException;