diff --git a/app/Http/Controllers/ConcertOrdersController.php b/app/Http/Controllers/ConcertOrdersController.php
index 17e9a23..9397045 100644
--- a/app/Http/Controllers/ConcertOrdersController.php
+++ b/app/Http/Controllers/ConcertOrdersController.php
@@ -32,6 +32,7 @@ class ConcertOrdersController extends Controller
             $this->paymentGateway->charge(request('ticket_quantity') * $concert->ticket_price, request('payment_token'));
             return response()->json([], 201);
         } catch (PaymentFailedException $e) {
+            $order->cancel();
             return response()->json([], 422);
         } catch (NotEnoughTicketsException $e) {
             return response()->json([], 422);
diff --git a/app/Order.php b/app/Order.php
index fdd6420..78da2e4 100644
--- a/app/Order.php
+++ b/app/Order.php
@@ -12,4 +12,13 @@ class Order extends Model
     {
         return $this->hasMany(Ticket::class);
     }
+
+    public function cancel()
+    {
+        foreach ($this->tickets as $ticket) {
+            $ticket->update(['order_id' => null]);
+        }
+
+        $this->delete();
+    }
 }
diff --git a/app/Ticket.php b/app/Ticket.php
index 5c90f58..94a8608 100644
--- a/app/Ticket.php
+++ b/app/Ticket.php
@@ -6,6 +6,8 @@ use Illuminate\Database\Eloquent\Model;
 
 class Ticket extends Model
 {
+    protected $guarded = [];
+
     public function scopeAvailable($query)
     {
         return $query->whereNull('order_id');
diff --git a/tests/unit/OrderTest.php b/tests/unit/OrderTest.php
new file mode 100644
index 0000000..18f88e9
--- /dev/null
+++ b/tests/unit/OrderTest.php
@@ -0,0 +1,26 @@
+<?php
+
+use App\Order;
+use App\Concert;
+use Illuminate\Foundation\Testing\WithoutMiddleware;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+
+class OrderTest extends TestCase
+{
+    use DatabaseMigrations;
+
+    /** @test */
+    function tickets_are_released_when_an_order_is_cancelled()
+    {
+        $concert = factory(Concert::class)->create();
+        $concert->addTickets(10);
+        $order = $concert->orderTickets('jane@example.com', 5);
+        $this->assertEquals(5, $concert->ticketsRemaining());
+
+        $order->cancel();
+
+        $this->assertEquals(10, $concert->ticketsRemaining());
+        $this->assertNull(Order::find($order->id));
+    }
+}