diff --git a/app/Billing/FakePaymentGateway.php b/app/Billing/FakePaymentGateway.php
index 2a87ddb..f30f1ef 100644
--- a/app/Billing/FakePaymentGateway.php
+++ b/app/Billing/FakePaymentGateway.php
@@ -4,6 +4,8 @@ namespace App\Billing;
 
 class FakePaymentGateway implements PaymentGateway
 {
+    const TEST_CARD_NUMBER = '4242424242424242';
+
     private $charges;
     private $tokens;
     private $beforeFirstChargeCallback;
@@ -14,7 +16,7 @@ class FakePaymentGateway implements PaymentGateway
         $this->tokens = collect();
     }
 
-    public function getValidTestToken($cardNumber = '4242424242424242')
+    public function getValidTestToken($cardNumber = self::TEST_CARD_NUMBER)
     {
         $token = 'fake-tok_'.str_random(24);
         $this->tokens[$token] = $cardNumber;
diff --git a/app/Billing/StripePaymentGateway.php b/app/Billing/StripePaymentGateway.php
index 14d2c83..317c9d2 100644
--- a/app/Billing/StripePaymentGateway.php
+++ b/app/Billing/StripePaymentGateway.php
@@ -2,11 +2,12 @@
 
 namespace App\Billing;
 
-use Stripe\Charge;
 use Stripe\Error\InvalidRequest;
 
 class StripePaymentGateway implements PaymentGateway
 {
+    const TEST_CARD_NUMBER = '4242424242424242';
+
     private $apiKey;
 
     public function __construct($apiKey)
@@ -17,21 +18,26 @@ class StripePaymentGateway implements PaymentGateway
     public function charge($amount, $token)
     {
         try {
-            Charge::create([
+            $stripeCharge = \Stripe\Charge::create([
                 'amount' => $amount,
                 'source' => $token,
                 'currency' => 'usd',
             ], ['api_key' => $this->apiKey]);
+
+            return new Charge([
+                'amount' => $stripeCharge['amount'],
+                'card_last_four' => $stripeCharge['source']['last4'],
+            ]);
         } catch (InvalidRequest $e) {
             throw new PaymentFailedException;
         }
     }
 
-    public function getValidTestToken()
+    public function getValidTestToken($cardNumber = self::TEST_CARD_NUMBER)
     {
         return \Stripe\Token::create([
             "card" => [
-                "number" => "4242424242424242",
+                "number" => $cardNumber,
                 "exp_month" => 1,
                 "exp_year" => date('Y') + 1,
                 "cvc" => "123"
@@ -43,7 +49,12 @@ class StripePaymentGateway implements PaymentGateway
     {
         $latestCharge = $this->lastCharge();
         $callback($this);
-        return $this->newChargesSince($latestCharge)->pluck('amount');
+        return $this->newChargesSince($latestCharge)->map(function ($stripeCharge) {
+            return new Charge([
+                'amount' => $stripeCharge['amount'],
+                'card_last_four' => $stripeCharge['source']['last4'],
+            ]);
+        });
     }
 
     private function lastCharge()
diff --git a/tests/unit/Billing/PaymentGatewayContractTests.php b/tests/unit/Billing/PaymentGatewayContractTests.php
index 62bde6c..e1f8b37 100644
--- a/tests/unit/Billing/PaymentGatewayContractTests.php
+++ b/tests/unit/Billing/PaymentGatewayContractTests.php
@@ -24,9 +24,9 @@ trait PaymentGatewayContractTests
     {
         $paymentGateway = $this->getPaymentGateway();
 
-        $charge = $paymentGateway->charge(2500, $paymentGateway->getValidTestToken('0000000000004242'));
+        $charge = $paymentGateway->charge(2500, $paymentGateway->getValidTestToken($paymentGateway::TEST_CARD_NUMBER));
 
-        $this->assertEquals('4242', $charge->cardLastFour());
+        $this->assertEquals(substr($paymentGateway::TEST_CARD_NUMBER, -4), $charge->cardLastFour());
         $this->assertEquals(2500, $charge->amount());
     }