diff --git a/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php b/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php
index d8152edd22de..77da3ce3e7a8 100644
--- a/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php
+++ b/src/Symfony/Component/HttpKernel/EventListener/ErrorListener.php
@@ -99,7 +99,7 @@ public function onControllerArguments(ControllerArgumentsEvent $event)
         $r = new \ReflectionFunction(\Closure::fromCallable($event->getController()));
         $r = $r->getParameters()[$k] ?? null;
 
-        if ($r && $r->hasType() && FlattenException::class === $r->getType()->getName()) {
+        if ($r && (!$r->hasType() || FlattenException::class === $r->getType()->getName())) {
             $arguments = $event->getArguments();
             $arguments[$k] = FlattenException::createFromThrowable($e);
             $event->setArguments($arguments);
diff --git a/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php b/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php
index ae7149199f96..cdf6874f359b 100644
--- a/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/EventListener/ErrorListenerTest.php
@@ -13,8 +13,8 @@
 
 use PHPUnit\Framework\TestCase;
 use Psr\Log\LoggerInterface;
-use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\ErrorHandler\Exception\FlattenException;
+use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Controller\ArgumentResolver;
@@ -158,12 +158,11 @@ public function testCSPHeaderIsRemoved()
         $this->assertFalse($dispatcher->hasListeners(KernelEvents::RESPONSE), 'CSP removal listener has been removed');
     }
 
-    public function testOnControllerArguments()
+    /**
+     * @dataProvider controllerProvider
+     */
+    public function testOnControllerArguments(callable $controller)
     {
-        $controller = function (FlattenException $exception) {
-            return new Response('OK: '.$exception->getMessage());
-        };
-
         $listener = new ErrorListener($controller, $this->createMock(LoggerInterface::class), true);
 
         $kernel = $this->createMock(HttpKernelInterface::class);
@@ -181,6 +180,23 @@ public function testOnControllerArguments()
 
         $this->assertSame('OK: foo', $event->getResponse()->getContent());
     }
+
+    public function controllerProvider()
+    {
+        yield [function (FlattenException $exception) {
+            return new Response('OK: '.$exception->getMessage());
+        }];
+
+        yield [function ($exception) {
+            $this->assertInstanceOf(FlattenException::class, $exception);
+
+            return new Response('OK: '.$exception->getMessage());
+        }];
+
+        yield [function (\Throwable $exception) {
+            return new Response('OK: '.$exception->getMessage());
+        }];
+    }
 }
 
 class TestLogger extends Logger implements DebugLoggerInterface