diff --git a/Provider/GuardAuthenticationProvider.php b/Provider/GuardAuthenticationProvider.php
index a34c2db..3467a32 100644
--- a/Provider/GuardAuthenticationProvider.php
+++ b/Provider/GuardAuthenticationProvider.php
@@ -105,7 +105,10 @@ private function authenticateViaGuard(AuthenticatorInterface $guardAuthenticator
         $user = $guardAuthenticator->getUser($token->getCredentials(), $this->userProvider);
 
         if (null === $user) {
-            throw new UsernameNotFoundException(sprintf('Null returned from "%s::getUser()".', \get_class($guardAuthenticator)));
+            $e = new UsernameNotFoundException(sprintf('Null returned from "%s::getUser()".', \get_class($guardAuthenticator)));
+            $e->setUsername($token->getUsername());
+
+            throw $e;
         }
 
         if (!$user instanceof UserInterface) {