diff --git a/package_manager/tests/fixtures/updated_module/1.0.0/src/PreUpdateService.php b/package_manager/tests/fixtures/updated_module/1.0.0/src/PreUpdateService.php
index 04eeb396d60fa51c4b963919430a3a5444465686..dfe58ac336f1de782481c06a84ce6d84f9ebb760 100644
--- a/package_manager/tests/fixtures/updated_module/1.0.0/src/PreUpdateService.php
+++ b/package_manager/tests/fixtures/updated_module/1.0.0/src/PreUpdateService.php
@@ -3,7 +3,7 @@
 namespace Drupal\updated_module;
 
 /**
- * Class for pre update services.
+ * A generic service class to prove that services are reloaded after an update.
  */
 class PreUpdateService {
 
diff --git a/package_manager/tests/fixtures/updated_module/1.1.0/src/PostUpdateService.php b/package_manager/tests/fixtures/updated_module/1.1.0/src/PostUpdateService.php
index e8063e78642a8e0e4925dd296fc7c2facc26b6f7..e01fb5ec7f17632e246325ae0c0fd0983d73699d 100644
--- a/package_manager/tests/fixtures/updated_module/1.1.0/src/PostUpdateService.php
+++ b/package_manager/tests/fixtures/updated_module/1.1.0/src/PostUpdateService.php
@@ -3,7 +3,7 @@
 namespace Drupal\updated_module;
 
 /**
- * Class for post update services.
+ * A generic service class to prove that services are reloaded after an update.
  */
 class PostUpdateService {
 
diff --git a/package_manager/tests/modules/package_manager_test_api/src/SystemChangeRecorder.php b/package_manager/tests/modules/package_manager_test_api/src/SystemChangeRecorder.php
index 3063937d6d5f4c0a52482e9b4990b4165ae883c4..6fb48ea54a0ddce855a03784a5aff4605b104714 100644
--- a/package_manager/tests/modules/package_manager_test_api/src/SystemChangeRecorder.php
+++ b/package_manager/tests/modules/package_manager_test_api/src/SystemChangeRecorder.php
@@ -64,7 +64,7 @@ class SystemChangeRecorder implements EventSubscriberInterface {
    * @param \Drupal\user\PermissionHandlerInterface $permissionHandler
    *   The permission handler service.
    * @param object $changedService
-   *   The changed service.
+   *   A generic service which will be different after the update.
    */
   public function __construct(PathLocator $path_locator, StateInterface $state, RouterInterface $router, PermissionHandlerInterface $permissionHandler, object $changedService) {
     $this->pathLocator = $path_locator;