symfony
diff --git a/‎src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
+5-1Lines changed: 5 additions & 1 deletion b/‎src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/EventDispatcher/DependencyInjection/RegisterListenersPass.php
+5-1Lines changed: 5 additions & 1 deletion
diff --git a/‎src/Symfony/Component/HttpKernel/DependencyInjection/FragmentRendererPass.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/DependencyInjection/FragmentRendererPass.php
+5Lines changed: 5 additions & 0 deletions b/‎src/Symfony/Component/HttpKernel/DependencyInjection/FragmentRendererPass.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/HttpKernel/DependencyInjection/FragmentRendererPass.php
+5Lines changed: 5 additions & 0 deletions
@@ -97,9 +97,13 @@ public function process(ContainerBuilder $container)
 
             // 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());
-
             $interface = 'Symfony\Component\EventDispatcher\EventSubscriberInterface';
+
             if (!is_subclass_of($class, $interface)) {
+                if (!class_exists($class, false)) {
+                    throw new \InvalidArgumentException(sprintf('Class "%s" used for service "%s" can not be found.', $class, $id));
+                }
+
                 throw new \InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $id, $interface));
             }
 
 
@@ -54,7 +54,12 @@ public function process(ContainerBuilder $container)
 
             $class = $container->getParameterBag()->resolveValue($def->getClass());
             $interface = 'Symfony\Component\HttpKernel\Fragment\FragmentRendererInterface';
+
             if (!is_subclass_of($class, $interface)) {
+                if (!class_exists($class, false)) {
+                    throw new \InvalidArgumentException(sprintf('Class "%s" used for service "%s" can not be found.', $class, $id));
+                }
+
                 throw new \InvalidArgumentException(sprintf('Service "%s" must implement interface "%s".', $id, $interface));
             }