diff --git a/core/modules/simpletest/src/KernelTestBase.php b/core/modules/simpletest/src/KernelTestBase.php
index 7607b4e..d3a16cc 100644
--- a/core/modules/simpletest/src/KernelTestBase.php
+++ b/core/modules/simpletest/src/KernelTestBase.php
@@ -193,7 +193,7 @@ protected function setUp() {
     }
     $this->kernel->boot();
 
-    // Ensure database tasks have been run.
+    // Ensure database install tasks have been run.
     require_once __DIR__ . '/../../../includes/install.inc';
     $connection = Database::getConnection();
     $errors = db_installer_object($connection->driver())->runTasks();
@@ -201,10 +201,10 @@ protected function setUp() {
       $this->fail('Failed to run installer database tasks: ' . implode(', ', $errors));
     }
 
-    // After running the database tasks we have to reboot the container so that
-    // a new database connection is created on the container. This prevents any
-    // services created during the first boot from having stale database
-    // connections, for example, \Drupal\Core\Config\DatabaseStorage.
+    // Reboot the kernel because the container might contain a connection to the
+    // database that has been closed during the database install tasks. This
+    // prevents any services created during the first boot from having stale
+    // database connections, for example, \Drupal\Core\Config\DatabaseStorage.
     $this->kernel->shutdown();
     $this->kernel->boot();