diff --git a/core/modules/simpletest/tests/src/TestBaseTest.php b/core/modules/simpletest/tests/src/TestBaseTest.php
index 9a23914..14fe873 100644
--- a/core/modules/simpletest/tests/src/TestBaseTest.php
+++ b/core/modules/simpletest/tests/src/TestBaseTest.php
@@ -64,7 +64,7 @@ public function testRandomStringValidate($string, $expected) {
   }
 
   /**
-   * Tests that the random strings contains a non-alphanumeric character.
+   * Tests that the random string contains a non-alphanumeric character.
    *
    * @see \Drupal\simpletest\TestBase::randomString().
    *