diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 3a8afdf..95d7f47 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -478,6 +478,9 @@ function install_begin_request(&$install_state) {
     // supported by \Drupal\Core\Config\InstallStorage since loading a
     // non-existing file would throw an exception.
     $container->get('config.factory')->setOverrideState(FALSE);
+
+    $container->register('size', 'Drupal\Core\Utility\Size')
+      ->addArgument(new Reference('string_translation'));
   }
 
   // Set the request in the kernel to the new created Request above
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index cf162fd..f01291c 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -1061,6 +1061,8 @@ private function prepareEnvironment() {
       ->addArgument(new Reference('language.default'));
     $this->container->register('string_translation', 'Drupal\Core\StringTranslation\TranslationManager')
       ->addArgument(new Reference('language_manager'));
+    $this->container->register('size', 'Drupal\Core\Utility\Size')
+      ->addArgument(new Reference('string_translation'));
 
     // Register info parser.
     $this->container->register('info_parser', 'Drupal\Core\Extension\InfoParser');
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 8143d71..7206874 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -1252,7 +1252,7 @@ protected function curlExec($curl_options, $redirect = FALSE) {
       '!method' => !empty($curl_options[CURLOPT_NOBODY]) ? 'HEAD' : (empty($curl_options[CURLOPT_POSTFIELDS]) ? 'GET' : 'POST'),
       '@url' => isset($original_url) ? $original_url : $url,
       '@status' => $status,
-      '!length' => $this->container->get('size')->format(strlen($this->drupalGetContent()))
+      '!length' => \Drupal::service('size')->format(strlen($this->drupalGetContent()))
     );
     $message = String::format('!method @url returned @status (!length).', $message_vars);
     $this->assertTrue($this->drupalGetContent() !== FALSE, $message, 'Browser');
diff --git a/core/modules/system/lib/Drupal/system/Tests/Bootstrap/MiscUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Bootstrap/MiscUnitTest.php
index f94c419..1f69fac 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Bootstrap/MiscUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Bootstrap/MiscUnitTest.php
@@ -7,12 +7,12 @@
 
 namespace Drupal\system\Tests\Bootstrap;
 
-use Drupal\simpletest\UnitTestBase;
+use Drupal\simpletest\DrupalUnitTestBase;
 
 /**
  * Tests miscellaneous functions in bootstrap.inc.
  */
-class MiscUnitTest extends UnitTestBase {
+class MiscUnitTest extends DrupalUnitTestBase {
 
   public static function getInfo() {
     return array(