diff -u b/core/lib/Drupal/Core/Site/Settings.php b/core/lib/Drupal/Core/Site/Settings.php
--- b/core/lib/Drupal/Core/Site/Settings.php
+++ b/core/lib/Drupal/Core/Site/Settings.php
@@ -46,7 +46,7 @@
    * @return \Drupal\Core\Site\Settings
    *
    * @throws \BadMethodCallException
-   *  Thrown when the settings instance called before being initialized.
+   *  Thrown when the settings instance has not been initialized yet.
    */
   public static function getInstance() {
     if (self::$instance === NULL) {
diff -u b/core/tests/Drupal/Tests/Core/Site/SettingsTest.php b/core/tests/Drupal/Tests/Core/Site/SettingsTest.php
--- b/core/tests/Drupal/Tests/Core/Site/SettingsTest.php
+++ b/core/tests/Drupal/Tests/Core/Site/SettingsTest.php
@@ -127,7 +127,7 @@
   }
 
   /**
-   * Tests Settings::testGetInstanceReflection().
+   * Tests that an exception is thrown when settings are not initialized yet.
    *
    * @covers ::getInstance
    */