diff --git a/lib/public/User/Events/UserFirstTimeLoggedInEvent.php b/lib/public/User/Events/UserFirstTimeLoggedInEvent.php
index 8abfc781885..718a64a601a 100644
--- a/lib/public/User/Events/UserFirstTimeLoggedInEvent.php
+++ b/lib/public/User/Events/UserFirstTimeLoggedInEvent.php
@@ -10,12 +10,14 @@ declare(strict_types=1);
 namespace OCP\User\Events;
 
 use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IWebhookCompatibleEvent;
+use OCP\EventDispatcher\JsonSerializer;
 use OCP\IUser;
 
 /**
  * @since 28.0.0
  */
-class UserFirstTimeLoggedInEvent extends Event {
+class UserFirstTimeLoggedInEvent extends Event implements IWebhookCompatibleEvent {
 	/**
 	 * @since 28.0.0
 	 */
@@ -31,4 +33,14 @@ class UserFirstTimeLoggedInEvent extends Event {
 	public function getUser(): IUser {
 		return $this->user;
 	}
+
+	/**
+	 * @since 34.0.0
+	 */
+	#[\Override]
+	public function getWebhookSerializable(): array {
+		return [
+			'user' => JsonSerializer::serializeUser($this->user)
+		];
+	}
 }