diff --git a/core/modules/system/src/Tests/Installer/InstallerTest.php b/core/modules/system/src/Tests/Installer/InstallerTest.php
index 0b63e04..74f1c5c 100644
--- a/core/modules/system/src/Tests/Installer/InstallerTest.php
+++ b/core/modules/system/src/Tests/Installer/InstallerTest.php
@@ -36,7 +36,10 @@ public function testInstaller() {
    * Installer step: Select language.
    */
   protected function setUpLanguage() {
+    // Test that \Drupal\Core\Render\BareHtmlPageRenderer adds assets and
+    // metatags as expected to the first page of the installer.
     $this->assertRaw('core/themes/seven/css/components/buttons.css', 'Seven\'s css is attached.');
+    $this->assertRaw('<meta name="charset" charset="utf-8" />', 'The installer page character set is set to utf-8.');
     parent::setUpLanguage();
   }
 }