diff --git a/core/modules/system/tests/modules/system_mail_failure_test/lib/Drupal/system_mail_failure_test/TestPhpMailFailure.php b/core/modules/system/tests/modules/system_mail_failure_test/lib/Drupal/system_mail_failure_test/TestPhpMailFailure.php
index dffba49..a719d7a 100644
--- a/core/modules/system/tests/modules/system_mail_failure_test/lib/Drupal/system_mail_failure_test/TestPhpMailFailure.php
+++ b/core/modules/system/tests/modules/system_mail_failure_test/lib/Drupal/system_mail_failure_test/TestPhpMailFailure.php
@@ -11,12 +11,12 @@
 use Drupal\Core\Mail\MailInterface;
 
 /**
- * Defines a mail sending implementation that return false.
+ * Defines a mail sending implementation that returns false.
  *
  * This class is for running tests or for development. To use set the
  * configuration:
  * @code
- * config('system.mail')->set('interface.default', 'Drupal\system_mail_failure_test\TestPhpMailFailure')->save();
+ *   config('system.mail')->set('interface.default', 'Drupal\system_mail_failure_test\TestPhpMailFailure')->save();
  * @endcode
  */
 class TestPhpMailFailure extends PhpMail implements MailInterface {
diff --git a/core/modules/system/tests/modules/system_mail_failure_test/system_mail_failure_test.module b/core/modules/system/tests/modules/system_mail_failure_test/system_mail_failure_test.module
index 5015a01..6acb6c4 100644
--- a/core/modules/system/tests/modules/system_mail_failure_test/system_mail_failure_test.module
+++ b/core/modules/system/tests/modules/system_mail_failure_test/system_mail_failure_test.module
@@ -2,6 +2,6 @@
 
 /**
  * @file
- * Disables the email function for testing purpose.
+ * Disables the email function for testing purposes.
  */