diff --git a/src/Symfony/Component/Config/Resource/ReflectionClassResource.php b/src/Symfony/Component/Config/Resource/ReflectionClassResource.php
index a8e1f9611b..735784ad64 100644
--- a/src/Symfony/Component/Config/Resource/ReflectionClassResource.php
+++ b/src/Symfony/Component/Config/Resource/ReflectionClassResource.php
@@ -11,6 +11,9 @@
 
 namespace Symfony\Component\Config\Resource;
 
+use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
 /**
  * @author Nicolas Grekas <p@tchwork.com>
  */
@@ -114,7 +117,9 @@ class ReflectionClassResource implements SelfCheckingResourceInterface, \Seriali
 
     private function generateSignature(\ReflectionClass $class)
     {
-        yield $class->getDocComment().$class->getModifiers();
+        yield $class->getDocComment();
+        yield (int) $class->isFinal();
+        yield (int) $class->isAbstract();
 
         if ($class->isTrait()) {
             yield print_r(class_uses($class->name), true);
@@ -149,6 +154,16 @@ class ReflectionClassResource implements SelfCheckingResourceInterface, \Seriali
                 yield print_r($defaults, true);
             }
         }
+
+        if ($class->isSubclassOf(EventSubscriberInterface::class)) {
+            yield EventSubscriberInterface::class;
+            yield print_r(\call_user_func(array($class->name, 'getSubscribedEvents')), true);
+        }
+
+        if ($class->isSubclassOf(ServiceSubscriberInterface::class)) {
+            yield ServiceSubscriberInterface::class;
+            yield print_r(\call_user_func(array($class->name, 'getSubscribedServices')), true);
+        }
     }
 }
 
diff --git a/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php b/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php
index 4eca3d50e4..3f13096f0a 100644
--- a/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php
+++ b/src/Symfony/Component/Config/Tests/Resource/ReflectionClassResourceTest.php
@@ -13,6 +13,8 @@ namespace Symfony\Component\Config\Tests\Resource;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\Resource\ReflectionClassResource;
+use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 class ReflectionClassResourceTest extends TestCase
 {
@@ -136,8 +138,52 @@ EOPHP;
         yield array(0, 14, '/** priv docblock */');
         yield array(0, 15, '');
     }
+
+    public function testEventSubscriber()
+    {
+        $res = new ReflectionClassResource(new \ReflectionClass(TestEventSubscriber::class));
+        $this->assertTrue($res->isFresh(0));
+
+        TestEventSubscriber::$subscribedEvents = array(123);
+        $this->assertFalse($res->isFresh(0));
+
+        $res = new ReflectionClassResource(new \ReflectionClass(TestEventSubscriber::class));
+        $this->assertTrue($res->isFresh(0));
+    }
+
+    public function testServiceSubscriber()
+    {
+        $res = new ReflectionClassResource(new \ReflectionClass(TestServiceSubscriber::class));
+        $this->assertTrue($res->isFresh(0));
+
+        TestServiceSubscriber::$subscribedServices = array(123);
+        $this->assertFalse($res->isFresh(0));
+
+        $res = new ReflectionClassResource(new \ReflectionClass(TestServiceSubscriber::class));
+        $this->assertTrue($res->isFresh(0));
+    }
 }
 
 interface DummyInterface
 {
 }
+
+class TestEventSubscriber implements EventSubscriberInterface
+{
+    public static $subscribedEvents = array();
+
+    public static function getSubscribedEvents()
+    {
+        return self::$subscribedEvents;
+    }
+}
+
+class TestServiceSubscriber implements ServiceSubscriberInterface
+{
+    public static $subscribedServices = array();
+
+    public static function getSubscribedServices()
+    {
+        return self::$subscribedServices;
+    }
+}
diff --git a/src/Symfony/Component/Config/composer.json b/src/Symfony/Component/Config/composer.json
index 6f759720e6..ab26402819 100644
--- a/src/Symfony/Component/Config/composer.json
+++ b/src/Symfony/Component/Config/composer.json
@@ -22,7 +22,8 @@
     "require-dev": {
         "symfony/finder": "~3.3|~4.0",
         "symfony/yaml": "~3.0|~4.0",
-        "symfony/dependency-injection": "~3.3|~4.0"
+        "symfony/dependency-injection": "~3.3|~4.0",
+        "symfony/event-dispatcher": "~3.3|~4.0"
     },
     "conflict": {
         "symfony/finder": "<3.3",
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php b/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php
index 4ed990ac08..572eabb7d9 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/RegisterServiceSubscribersPass.php
@@ -56,14 +56,14 @@ class RegisterServiceSubscribersPass extends AbstractRecursivePass
         }
         $class = $value->getClass();
 
-        if (!is_subclass_of($class, ServiceSubscriberInterface::class)) {
-            if (!class_exists($class, false)) {
-                throw new InvalidArgumentException(sprintf('Class "%s" used for service "%s" cannot be found.', $class, $this->currentId));
-            }
-
+        if (!$r = $this->container->getReflectionClass($class)) {
+            throw new InvalidArgumentException(sprintf('Class "%s" used for service "%s" cannot be found.', $class, $this->currentId));
+        }
+        if (!$r->isSubclassOf(ServiceSubscriberInterface::class)) {
             throw new InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $this->currentId, ServiceSubscriberInterface::class));
         }
-        $this->container->addObjectResource($class);
+        $class = $r->name;
+
         $subscriberMap = array();
         $declaringClass = (new \ReflectionMethod($class, 'getSubscribedServices'))->class;
 
diff --git a/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php b/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
index 9f9c09c528..ff636d6180 100644
--- a/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
+++ b/src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
@@ -89,17 +89,15 @@ class RegisterListenersPass implements CompilerPassInterface
             $def = $container->getDefinition($id);
 
             // We must assume that the class value has been correctly filled, even if the service is created by a factory
-            $class = $container->getParameterBag()->resolveValue($def->getClass());
-            $interface = 'Symfony\Component\EventDispatcher\EventSubscriberInterface';
+            $class = $def->getClass();
 
-            if (!is_subclass_of($class, $interface)) {
-                if (!class_exists($class, false)) {
-                    throw new InvalidArgumentException(sprintf('Class "%s" used for service "%s" cannot be found.', $class, $id));
-                }
-
-                throw new InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $id, $interface));
+            if (!$r = $container->getReflectionClass($class)) {
+                throw new InvalidArgumentException(sprintf('Class "%s" used for service "%s" cannot be found.', $class, $id));
             }
-            $container->addObjectResource($class);
+            if (!$r->isSubclassOf(EventSubscriberInterface::class)) {
+                throw new InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $id, EventSubscriberInterface::class));
+            }
+            $class = $r->name;
 
             ExtractingEventDispatcher::$subscriber = $class;
             $extractingDispatcher->addSubscriber($extractingDispatcher);