diff --git a/tests/unit/Billing/FakePaymentGatewayTest.php b/tests/unit/Billing/FakePaymentGatewayTest.php
index f623a82..ab66b71 100644
--- a/tests/unit/Billing/FakePaymentGatewayTest.php
+++ b/tests/unit/Billing/FakePaymentGatewayTest.php
@@ -15,19 +15,6 @@ class FakePaymentGatewayTest extends TestCase
         return new FakePaymentGateway;
     }
 
-    /** @test */
-    function charges_with_an_invalid_payment_token_fail()
-    {
-        try {
-            $paymentGateway = new FakePaymentGateway;
-            $paymentGateway->charge(2500, 'invalid-payment-token');
-        } catch (PaymentFailedException $e) {
-            return;
-        }
-
-        $this->fail();
-    }
-
     /** @test */
     function running_a_hook_before_the_first_charge()
     {
diff --git a/tests/unit/Billing/PaymentGatewayContractTests.php b/tests/unit/Billing/PaymentGatewayContractTests.php
index 1c3b4cb..04025db 100644
--- a/tests/unit/Billing/PaymentGatewayContractTests.php
+++ b/tests/unit/Billing/PaymentGatewayContractTests.php
@@ -1,5 +1,7 @@
 <?php
 
+use App\Billing\PaymentFailedException;
+
 trait PaymentGatewayContractTests
 {
     abstract protected function getPaymentGateway();
@@ -17,6 +19,24 @@ trait PaymentGatewayContractTests
         $this->assertEquals(2500, $newCharges->sum());
     }
 
+    /** @test */
+    function charges_with_an_invalid_payment_token_fail()
+    {
+        $paymentGateway = $this->getPaymentGateway();
+
+        $newCharges = $paymentGateway->newChargesDuring(function ($paymentGateway) {
+            try {
+                $paymentGateway->charge(2500, 'invalid-payment-token');
+            } catch (PaymentFailedException $e) {
+                return;
+            }
+
+            $this->fail("Charging with an invalid payment token did not throw a PaymentFailedException.");
+        });
+
+        $this->assertCount(0, $newCharges);
+    }
+
     /** @test */
     function can_fetch_charges_created_during_a_callback()
     {
diff --git a/tests/unit/Billing/StripePaymentGatewayTest.php b/tests/unit/Billing/StripePaymentGatewayTest.php
index 829a441..07ec889 100644
--- a/tests/unit/Billing/StripePaymentGatewayTest.php
+++ b/tests/unit/Billing/StripePaymentGatewayTest.php
@@ -10,58 +10,8 @@ class StripePaymentGatewayTest extends TestCase
 {
     use PaymentGatewayContractTests;
 
-    protected function setUp()
-    {
-        parent::setUp();
-        $this->lastCharge = $this->lastCharge();
-    }
-
     protected function getPaymentGateway()
     {
         return new StripePaymentGateway(config('services.stripe.secret'));
     }
-
-    /** @test */
-    function charges_with_an_invalid_payment_token_fail()
-    {
-        try {
-            $paymentGateway = new StripePaymentGateway(config('services.stripe.secret'));
-            $paymentGateway->charge(2500, 'invalid-payment-token');
-        } catch (PaymentFailedException $e) {
-            $this->assertCount(0, $this->newCharges());
-            return;
-        }
-
-        $this->fail("Charging with an invalid payment token did not throw a PaymentFailedException.");
-    }
-
-    private function lastCharge()
-    {
-        return array_first(\Stripe\Charge::all(
-            ['limit' => 1],
-            ['api_key' => config('services.stripe.secret')]
-        )['data']);
-    }
-
-    private function newCharges()
-    {
-        return \Stripe\Charge::all(
-            [
-                'ending_before' => $this->lastCharge ? $this->lastCharge->id : null,
-            ],
-            ['api_key' => config('services.stripe.secret')]
-        )['data'];
-    }
-
-    private function validToken()
-    {
-        return \Stripe\Token::create([
-            "card" => [
-                "number" => "4242424242424242",
-                "exp_month" => 1,
-                "exp_year" => date('Y') + 1,
-                "cvc" => "123"
-            ]
-        ], ['api_key' => config('services.stripe.secret')])->id;
-    }
 }