diff --git a/src/Core/Interfaces/BilletInterface.php b/src/Core/Interfaces/BilletInterface.php
index 205635f..8742317 100644
--- a/src/Core/Interfaces/BilletInterface.php
+++ b/src/Core/Interfaces/BilletInterface.php
@@ -12,7 +12,7 @@ interface BilletInterface
      */
     public function create(array $data);
 
-     /**
+    /**
     * Cancels a billet.
     *
     * @param string $transactionId Transaction ID to cancel.
diff --git a/src/Core/Interfaces/NotificationInterface.php b/src/Core/Interfaces/NotificationInterface.php
index bcb4c3c..8ec7c2e 100644
--- a/src/Core/Interfaces/NotificationInterface.php
+++ b/src/Core/Interfaces/NotificationInterface.php
@@ -7,8 +7,8 @@ interface NotificationInterface
     /**
      * Get notification's response.
      *
-     * @param string $notificationId  
-     * @param string $transactionId 
+     * @param string $notificationId
+     * @param string $transactionId
      * @return void
      */
     public function response(string $notificationId = '', string $transactionId = '');