diff --git a/src/Parsian/Parsian.php b/src/Parsian/Parsian.php
index f10e0ebd..59f47d86 100644
--- a/src/Parsian/Parsian.php
+++ b/src/Parsian/Parsian.php
@@ -145,7 +145,7 @@ protected function sendPayRequest()
 	 */
 	protected function verifyPayment()
 	{
-		if (!isset(Input::get('au')) && !isset(Input::get('rs')))
+		if (!Input::has('au') && !Input::has('rs'))
 			throw new ParsianErrorException('درخواست غیر معتبر', -1);
 
 		$authority = Input::get('au');