diff --git a/core/modules/system/src/Tests/Module/InstallTest.php b/core/modules/system/src/Tests/Module/InstallTest.php
index babdd76..720c801 100644
--- a/core/modules/system/src/Tests/Module/InstallTest.php
+++ b/core/modules/system/src/Tests/Module/InstallTest.php
@@ -29,18 +29,6 @@ public function testGetSchemaAtInstallTime() {
   }
 
   /**
-   * Tests enabling User module once more.
-   *
-   * Regression: The installer might enable a module twice due to automatic
-   * dependency resolution. A bug caused the stored weight for User module to
-   * be an array.
-   */
-  public function testEnableUserTwice() {
-    \Drupal::service('module_installer')->install(array('user'), FALSE);
-    $this->assertIdentical($this->config('core.extension')->get('module.user'), 0);
-  }
-
-  /**
    * Tests recorded schema versions of early installed modules in the installer.
    */
   public function testRequiredModuleSchemaVersions() {
@@ -58,36 +46,20 @@ public function testRequiredModuleSchemaVersions() {
    * Ensures that post update functions are removed on uninstall.
    */
   public function testUninstallPostUpdateFunctions() {
+    // First, to avoid false positives, ensure that the post_update function
+    // exists while the module is still installed.
+    $post_update_key_value = \Drupal::keyValue('post_update');
+    $existing_updates = $post_update_key_value->get('existing_updates', []);
+    $this->assertTrue(in_array('module_test_post_update_test', $existing_updates));
+
+    // Uninstall the module.
     \Drupal::service('module_installer')->uninstall(['module_test']);
 
+
+    // Ensure the post update function is no longer listed.
     $post_update_key_value = \Drupal::keyValue('post_update');
     $existing_updates = $post_update_key_value->get('existing_updates', []);
     $this->assertFalse(in_array('module_test_post_update_test', $existing_updates));
   }
 
-  /**
-   * Tests that an exception is thrown when a module name is too long.
-   */
-  public function testModuleNameLength() {
-    $module_name = 'invalid_module_name_over_the_maximum_allowed_character_length';
-    $message = format_string('Exception thrown when enabling module %name with a name length over the allowed maximum', array('%name' => $module_name));
-    try {
-      $this->container->get('module_installer')->install(array($module_name));
-      $this->fail($message);
-    }
-    catch (ExtensionNameLengthException $e) {
-      $this->pass($message);
-    }
-
-    // Since for the UI, the submit callback uses FALSE, test that too.
-    $message = format_string('Exception thrown when enabling as if via the UI the module %name with a name length over the allowed maximum', array('%name' => $module_name));
-    try {
-      $this->container->get('module_installer')->install(array($module_name), FALSE);
-      $this->fail($message);
-    }
-    catch (ExtensionNameLengthException $e) {
-      $this->pass($message);
-    }
-  }
-
 }
diff --git a/core/modules/system/src/Tests/Module/ModuleInstallerKernelTest.php b/core/modules/system/src/Tests/Module/ModuleInstallerKernelTest.php
new file mode 100644
index 0000000..eb34f8c
--- /dev/null
+++ b/core/modules/system/src/Tests/Module/ModuleInstallerKernelTest.php
@@ -0,0 +1,72 @@
+<?php
+
+namespace Drupal\system\Tests\Module;
+
+use Drupal\Core\Extension\ExtensionNameLengthException;
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\Component\Render\FormattableMarkup;
+
+/**
+ * Tests the installation of modules.
+ *
+ * @group Module
+ */
+class ModuleInstallerKernelTest extends KernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+    // @todo ModuleInstaller calls system_rebuild_module_data which is part of
+    // system.module, see https://www.drupal.org/node/2208429.
+    include_once $this->root . '/core/modules/system/system.module';
+    \Drupal::service('module_installer')->install([
+      'system',
+      'user',
+      'module_test',
+    ]);
+  }
+
+  /**
+   * Tests enabling User module once more.
+   *
+   * Regression: The installer might enable a module twice due to automatic
+   * dependency resolution. A bug caused the stored weight for User module to
+   * be an array.
+   */
+  public function testEnableUserTwice() {
+    \Drupal::service('module_installer')->install(['user'], FALSE);
+    $this->assertSame($this->config('core.extension')->get('module.user'), 0);
+
+    // To avoid false positives, ensure that a module that does not exist does
+    // not return exactly zero.
+    $this->assertNotSame($this->config('core.extension')->get('module.does_not_exist'), 0);
+  }
+
+  /**
+   * Tests that an exception is thrown when a module name is too long.
+   */
+  public function testModuleNameLength() {
+    $module_name = 'invalid_module_name_over_the_maximum_allowed_character_length';
+    $message = new FormattableMarkup('Exception thrown when enabling module %name with a name length over the allowed maximum', ['%name' => $module_name]);
+    try {
+      $this->container->get('module_installer')->install([$module_name]);
+      $this->fail($message->__toString());
+    }
+    catch (ExtensionNameLengthException $e) {
+      $this->assertTrue(TRUE, $message->__toString());
+    }
+
+    // Since for the UI, the submit callback uses FALSE, test that too.
+    $message = new FormattableMarkup('Exception thrown when enabling as if via the UI the module %name with a name length over the allowed maximum', ['%name' => $module_name]);
+    try {
+      $this->container->get('module_installer')->install([$module_name], FALSE);
+      $this->fail($message);
+    }
+    catch (ExtensionNameLengthException $e) {
+      $this->assertTrue(TRUE, $message->__toString());
+    }
+  }
+
+}