diff --git a/docs/en/index.rst b/docs/en/index.rst
index dd65787c..e269e05e 100644
--- a/docs/en/index.rst
+++ b/docs/en/index.rst
@@ -85,12 +85,12 @@ define the ``AuthenticationService`` it wants to use. Add the following method t
 
         // Define where users should be redirected to when they are not authenticated
         $service->setConfig([
-            'unauthenticatedRedirect' => Router::url([
+            'unauthenticatedRedirect' => [
                     'prefix' => false,
-                    'plugin' => null,
+                    'plugin' => false,
                     'controller' => 'Users',
                     'action' => 'login',
-            ]),
+            ],
             'queryParam' => 'redirect',
         ]);
 
diff --git a/src/AuthenticationService.php b/src/AuthenticationService.php
index da88ee40..69d0b1d3 100644
--- a/src/AuthenticationService.php
+++ b/src/AuthenticationService.php
@@ -26,6 +26,7 @@
 use Authentication\Identifier\IdentifierCollection;
 use Authentication\Identifier\IdentifierInterface;
 use Cake\Core\InstanceConfigTrait;
+use Cake\Routing\Router;
 use InvalidArgumentException;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
@@ -372,6 +373,9 @@ public function getUnauthenticatedRedirectUrl(ServerRequestInterface $request):
         if ($target === null) {
             return null;
         }
+        if (is_array($target) && class_exists(Router::class)) {
+            $target = Router::url($target);
+        }
         if ($param === null) {
             return $target;
         }
diff --git a/tests/TestCase/AuthenticationServiceTest.php b/tests/TestCase/AuthenticationServiceTest.php
index 4fa45df7..8d062952 100644
--- a/tests/TestCase/AuthenticationServiceTest.php
+++ b/tests/TestCase/AuthenticationServiceTest.php
@@ -32,6 +32,7 @@
 use Cake\Http\ServerRequest;
 use Cake\Http\ServerRequestFactory;
 use Cake\I18n\DateTime;
+use Cake\Routing\Router;
 use InvalidArgumentException;
 use Psr\Http\Message\RequestInterface;
 use Psr\Http\Message\ResponseInterface;
@@ -818,6 +819,30 @@ public function testGetUnauthenticatedRedirectUrl()
         );
     }
 
+    public function testGetUnauthenticatedRedirectUrlAsArray()
+    {
+        Router::fullBaseUrl('http://localhost');
+
+        $builder = Router::createRouteBuilder('/');
+        $builder->connect(
+            '/login',
+            ['controller' => 'Users', 'action' => 'login'],
+            ['_name' => 'login'],
+        );
+
+        $service = new AuthenticationService();
+        $request = ServerRequestFactory::fromGlobals(
+            ['REQUEST_URI' => '/secrets'],
+        );
+        $service->setConfig('unauthenticatedRedirect', [
+            'prefix' => false,
+            'plugin' => false,
+            'controller' => 'Users',
+            'action' => 'login',
+        ]);
+        $this->assertSame('/login', $service->getUnauthenticatedRedirectUrl($request));
+    }
+
     public function testGetUnauthenticatedRedirectUrlWithBasePath()
     {
         $request = ServerRequestFactory::fromGlobals(