diff --git a/src/Paystack.php b/src/Paystack.php
index a3646a1..16d596d 100644
--- a/src/Paystack.php
+++ b/src/Paystack.php
@@ -13,6 +13,8 @@
 
 use GuzzleHttp\Client;
 use Illuminate\Support\Facades\Config;
+use Unicodeveloper\Paystack\Exceptions\IsNullException;
+use Unicodeveloper\Paystack\Exceptions\PaymentVerificationFailedException;
 
 class Paystack {
 
@@ -170,7 +172,7 @@ public function isTransactionVerificationValid()
             case self::VS:
                 $validate = true;
                 break;
-            case self:ITF:
+            case self::ITF:
                 $validate = false;
                 break;
             default: