diff -u b/core/modules/forum/lib/Drupal/forum/Tests/ForumUninstallTest.php b/core/modules/forum/lib/Drupal/forum/Tests/ForumUninstallTest.php
--- b/core/modules/forum/lib/Drupal/forum/Tests/ForumUninstallTest.php
+++ b/core/modules/forum/lib/Drupal/forum/Tests/ForumUninstallTest.php
@@ -65,9 +65,9 @@
 
     $this->container->get('module_handler')->install(array('forum'));
     foreach ($module_list as $module) {
-      // Check that the module's database tables no longer exist.
+      // Check that the module's database tables exist.
       $this->assertModuleTablesExist($module);
-      // Check that the module's config files no longer exist.
+      // Check that the module's config files exist.
       $this->assertModuleConfig($module);
     }