diff --git a/core/lib/Drupal/Core/Update/UpdateServiceProvider.php b/core/lib/Drupal/Core/Update/UpdateServiceProvider.php
index 45ed20c168..0f50b090d7 100644
--- a/core/lib/Drupal/Core/Update/UpdateServiceProvider.php
+++ b/core/lib/Drupal/Core/Update/UpdateServiceProvider.php
@@ -5,6 +5,7 @@
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\DependencyInjection\ServiceModifierInterface;
 use Drupal\Core\DependencyInjection\ServiceProviderInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Reference;
 
@@ -51,9 +52,12 @@ protected function removeUndefinedServices(ContainerBuilder $container) {
       $definitions = $container->getDefinitions();
       foreach ($definitions as $key => $definition) {
         foreach ($definition->getArguments() as $argument) {
-          if ($argument instanceof Reference && !$container->has((string) $argument)) {
-            // If the container does not have the argument, remove the service.
-            $container->removeDefinition($key);
+          if ($argument instanceof Reference) {
+            if (!$container->has((string) $argument) && $argument->getInvalidBehavior() === ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE) {
+              // If the container does not have the argument but would throw an
+              // exception, remove the service.
+              $container->removeDefinition($key);
+            }
           }
         }
       }
diff --git a/core/modules/system/src/Tests/Update/UpdatePathNewDependencyTest.php b/core/modules/system/src/Tests/Update/UpdatePathNewDependencyTest.php
deleted file mode 100644
index 5408141c77..0000000000
--- a/core/modules/system/src/Tests/Update/UpdatePathNewDependencyTest.php
+++ /dev/null
@@ -1,48 +0,0 @@
-<?php
-
-namespace Drupal\system\Tests\Update;
-
-/**
- * Modules can introduce new dependencies and enable them in update hooks.
- *
- * @group system
- */
-class UpdatePathNewDependencyTest extends UpdatePathTestBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setDatabaseDumpFiles() {
-    $this->databaseDumpFiles = [
-      __DIR__ . '/../../../../system/tests/fixtures/update/drupal-8.bare.standard.php.gz',
-    ];
-  }
-
-  /**
-   * Test that a module can add services that depend on new modules.
-   */
-  public function testUpdateNewDependency() {
-    // The new_dependency_test before the update is just an empty info.yml file.
-    // The code of the new_dependency_test module is after the update and
-    // contains the dependency on the new_dependency_test_with_service module.
-    $extension_config = \Drupal::configFactory()->getEditable('core.extension');
-    $extension_config
-      ->set('module.new_dependency_test', 0)
-      ->set('module', module_config_sort($extension_config->get('module')))
-      ->save(TRUE);
-    drupal_set_installed_schema_version('new_dependency_test', \Drupal::CORE_MINIMUM_SCHEMA_VERSION);
-
-    // Running the updates enables the dependency.
-    $this->runUpdates();
-
-    $this->assertTrue(array_key_exists('new_dependency_test', \Drupal::config('core.extension')->get('module')));
-    $this->assertTrue(array_key_exists('new_dependency_test_with_service', \Drupal::config('core.extension')->get('module')));
-
-    // Rebuild the container and test that the new service works.
-    $this->rebuildContainer();
-    $this->assertEqual('Hello', \Drupal::service('new_dependency_test.dependent')->greet());
-    $this->assertEqual('Hello World', \Drupal::service('new_dependency_test.decorated')->greet());
-
-  }
-
-}
diff --git a/core/modules/system/tests/modules/new_dependency_test/new_dependency_test.services.yml b/core/modules/system/tests/modules/new_dependency_test/new_dependency_test.services.yml
index 56d2dfef9c..29a6de5b5f 100644
--- a/core/modules/system/tests/modules/new_dependency_test/new_dependency_test.services.yml
+++ b/core/modules/system/tests/modules/new_dependency_test/new_dependency_test.services.yml
@@ -5,5 +5,8 @@ services:
   new_dependency_test.decorated:
     class: Drupal\new_dependency_test\DecoratedDependentService
     arguments: ['@new_dependency_test.dependent']
+  new_dependency_test.decorated_optional:
+    class: Drupal\new_dependency_test\DecoratedDependentService
+    arguments: ['@?new_dependency_test.dependent']
   new_dependency_test.alias:
     alias: new_dependency_test.dependent
diff --git a/core/modules/system/tests/modules/new_dependency_test/src/DependentService.php b/core/modules/system/tests/modules/new_dependency_test/src/DependentService.php
index 22e1631a09..facf7de198 100644
--- a/core/modules/system/tests/modules/new_dependency_test/src/DependentService.php
+++ b/core/modules/system/tests/modules/new_dependency_test/src/DependentService.php
@@ -19,10 +19,10 @@ class DependentService {
   /**
    * DependentService constructor.
    *
-   * @param \Drupal\new_dependency_test_with_service\NewService $service
+   * @param \Drupal\new_dependency_test_with_service\NewService|null $service
    *   The service of the new module.
    */
-  public function __construct(NewService $service) {
+  public function __construct(NewService $service = null) {
     $this->service = $service;
   }
 
@@ -33,7 +33,10 @@ public function __construct(NewService $service) {
    *   The greeting.
    */
   public function greet() {
-    return $this->service->greet();
+    if (isset($this->service)) {
+      return $this->service->greet();
+    }
+    return 'Sorry, no service.';
   }
 
 }
diff --git a/core/modules/system/tests/src/Functional/Update/UpdatePathNewDependencyTest.php b/core/modules/system/tests/src/Functional/Update/UpdatePathNewDependencyTest.php
new file mode 100644
index 0000000000..e5d38ed595
--- /dev/null
+++ b/core/modules/system/tests/src/Functional/Update/UpdatePathNewDependencyTest.php
@@ -0,0 +1,63 @@
+<?php
+
+namespace Drupal\FunctionalTests\Update;
+
+/**
+ * Modules can introduce new dependencies and enable them in update hooks.
+ *
+ * @group system
+ */
+class UpdatePathNewDependencyTest extends UpdatePathTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setDatabaseDumpFiles() {
+    $this->databaseDumpFiles = [
+      __DIR__ . '/../../../../tests/fixtures/update/drupal-8.bare.standard.php.gz',
+    ];
+  }
+
+  /**
+   * Test that a module can add services that depend on new modules.
+   */
+  public function testUpdateNewDependency() {
+    // The new_dependency_test before the update is just an empty info.yml file.
+    // The code of the new_dependency_test module is after the update and
+    // contains the dependency on the new_dependency_test_with_service module.
+    $extension_config = $this->container->get('config.factory')->getEditable('core.extension');
+    $extension_config
+      ->set('module.new_dependency_test', 0)
+      ->set('module', module_config_sort($extension_config->get('module')))
+      ->save(TRUE);
+    drupal_set_installed_schema_version('new_dependency_test', \Drupal::CORE_MINIMUM_SCHEMA_VERSION);
+
+    // Rebuild the container and test that the service with the optional unmet
+    // dependency is still available while the ones that fail are not.
+    $this->rebuildContainer();
+    $this->container;
+
+    $this->assertFalse($this->container->has('new_dependency_test_with_service.service'));
+    $this->assertFalse($this->container->has('new_dependency_test.dependent'));
+    $this->assertFalse($this->container->has('new_dependency_test.decorated'));
+    $this->assertFalse($this->container->has('new_dependency_test.alias'));
+    $this->assertEquals('Sorry, no service.', $this->container->get('new_dependency_test.decorated_optional')->greet());
+
+
+    // Running the updates enables the dependency.
+    $this->runUpdates();
+
+    $this->assertTrue(array_key_exists('new_dependency_test', $this->container->get('config.factory')->get('core.extension')->get('module')));
+    $this->assertTrue(array_key_exists('new_dependency_test_with_service', $this->container->get('config.factory')->get('core.extension')->get('module')));
+
+    // Rebuild the container and test that the new service works.
+    $this->rebuildContainer();
+    $this->assertEquals('Hello', $this->container->get('new_dependency_test_with_service.service')->greet());
+    $this->assertEquals('Hello', $this->container->get('new_dependency_test.dependent')->greet());
+    $this->assertEquals('Hello', $this->container->get('new_dependency_test.alias')->greet());
+    $this->assertEquals('Hello World', $this->container->get('new_dependency_test.decorated')->greet());
+    $this->assertEquals('Hello World', $this->container->get('new_dependency_test.decorated_optional')->greet());
+
+  }
+
+}