diff --git a/src/Webhooks/Data/MessageFailedData.php b/src/Webhooks/Data/MessageFailedData.php
index 163e60f..b908444 100644
--- a/src/Webhooks/Data/MessageFailedData.php
+++ b/src/Webhooks/Data/MessageFailedData.php
@@ -9,7 +9,7 @@
      */
     public function __construct(
         public string $messageId,
-        public string $recipient,
+        public ?string $recipient,
         public string $reason,
         public ServerResponse $response,
         public array $metadata,
diff --git a/tests/Unit/Webhooks/WebhookEventTypeTest.php b/tests/Unit/Webhooks/WebhookEventTypeTest.php
index ed156d5..3e67997 100644
--- a/tests/Unit/Webhooks/WebhookEventTypeTest.php
+++ b/tests/Unit/Webhooks/WebhookEventTypeTest.php
@@ -102,6 +102,29 @@
     expect($event->data->subject)->toBe('Test Subject');
 });
 
+it('creates a failed message event with an optional recipient', function (?string $recipient) {
+    $payload = [
+        'id' => 'test-id',
+        'event' => 'message.failed',
+        'timestamp' => '2024-01-01T00:00:00Z',
+        'data' => [
+            'message_id' => 'msg-123',
+            'recipient' => $recipient,
+            'reason' => 'Expired',
+            'response' => ['status_code' => 500],
+            'metadata' => [],
+        ],
+    ];
+
+    $event = WebhookEventType::MessageFailed->toEvent($payload);
+
+    expect($event)->toBeInstanceOf(MessageFailed::class)
+        ->and($event->data->recipient)->toBe($recipient);
+})->with([
+    'recipient present' => 'test@example.com',
+    'recipient absent' => null,
+]);
+
 it('creates correct event class for WebhookTest', function () {
     $payload = [
         'id' => 'test-id',