diff --git a/src/Symfony/Component/DependencyInjection/Loader/FileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/FileLoader.php
index 40cf8f9ee4cae..dd8a39614468b 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/FileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/FileLoader.php
@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\DependencyInjection\Loader;
 
+use Symfony\Component\DependencyInjection\Alias;
 use Symfony\Component\DependencyInjection\ChildDefinition;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Definition;
@@ -58,12 +59,14 @@ public function registerClasses(Definition $prototype, $namespace, $resource, $e
             throw new InvalidArgumentException(sprintf('Namespace is not a valid PSR-4 prefix: %s.', $namespace));
         }
 
+        $public = $prototype->isPublic();
         $classes = $this->findClasses($namespace, $resource, $exclude);
         // prepare for deep cloning
         $prototype = serialize($prototype);
 
         foreach ($classes as $class) {
-            $this->setDefinition($class, unserialize($prototype));
+            $this->setDefinition("$class.prototype", unserialize($prototype)->setClass($class)->setPublic(false));
+            $this->container->setAlias($class, new Alias("$class.prototype", $public));
         }
     }
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php
index 15c827d8270df..98e121b65744d 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php
@@ -204,6 +204,12 @@ public function getYamlCompileTests()
             'child_service',
             'child_service_expected',
         );
+
+        yield array(
+            'psr4_prototype_parent_child',
+            'child_service',
+            'child_service_expected',
+        );
     }
 }
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/integration/psr4_prototype_parent_child/expected.yml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/integration/psr4_prototype_parent_child/expected.yml
new file mode 100644
index 0000000000000..f4ee3b02c6a55
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/integration/psr4_prototype_parent_child/expected.yml
@@ -0,0 +1,7 @@
+services:
+    child_service_expected:
+        class: Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\Sub\Bar
+        autoconfigure: false
+        autowire: true
+        public: true
+        arguments: ['dummy_arg']
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/integration/psr4_prototype_parent_child/main.yml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/integration/psr4_prototype_parent_child/main.yml
new file mode 100644
index 0000000000000..b34cf3f6679c3
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/integration/psr4_prototype_parent_child/main.yml
@@ -0,0 +1,16 @@
+services:
+    _defaults:
+        autoconfigure: true
+        autowire: true
+        public: false
+
+    Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\Sub\:
+        resource: '../../../Prototype/Sub'
+        arguments: ['dummy_arg']
+
+    child_service:
+        class: Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\Sub\Bar
+        parent: Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\Sub\Bar.prototype
+        public: true
+        autowire: true
+        autoconfigure: false
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php
index 6544145c4e0e0..5e0b0fd1dfa20 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/FileLoaderTest.php
@@ -88,9 +88,10 @@ public function testRegisterClasses()
         $loader->registerClasses(new Definition(), 'Symfony\Component\DependencyInjection\Tests\Fixtures\Prototype\Sub\\', 'Prototype/%sub_dir%/*');
 
         $this->assertEquals(
-            array('service_container', Bar::class),
+            array('service_container', Bar::class.'.prototype'),
             array_keys($container->getDefinitions())
         );
+        $this->assertSame(Bar::class.'.prototype', (string) $container->getAlias(Bar::class));
     }
 
     public function testRegisterClassesWithExclude()
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
index 9ffe5793e4764..4c8e6e56a147c 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
@@ -624,8 +624,9 @@ public function testPrototype()
 
         $ids = array_keys($container->getDefinitions());
         sort($ids);
-        $this->assertSame(array(Prototype\Foo::class, Prototype\Sub\Bar::class, 'service_container'), $ids);
-
+        $this->assertSame(array(Prototype\Foo::class.'.prototype', Prototype\Sub\Bar::class.'.prototype', 'service_container'), $ids);
+        $this->assertSame(Prototype\Foo::class.'.prototype', (string) $container->getAlias(Prototype\Foo::class));
+        $this->assertSame(Prototype\Sub\Bar::class.'.prototype', (string) $container->getAlias(Prototype\Sub\Bar::class));
         $resources = $container->getResources();
 
         $fixturesDir = dirname(__DIR__).DIRECTORY_SEPARATOR.'Fixtures'.DIRECTORY_SEPARATOR;
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
index b8ac2fc0e9296..856f342577c3c 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
@@ -376,7 +376,9 @@ public function testPrototype()
 
         $ids = array_keys($container->getDefinitions());
         sort($ids);
-        $this->assertSame(array(Prototype\Foo::class, Prototype\Sub\Bar::class, 'service_container'), $ids);
+        $this->assertSame(array(Prototype\Foo::class.'.prototype', Prototype\Sub\Bar::class.'.prototype', 'service_container'), $ids);
+        $this->assertSame(Prototype\Foo::class.'.prototype', (string) $container->getAlias(Prototype\Foo::class));
+        $this->assertSame(Prototype\Sub\Bar::class.'.prototype', (string) $container->getAlias(Prototype\Sub\Bar::class));
 
         $resources = $container->getResources();