diff --git a/core/lib/Drupal/Core/DependencyInjection/UpdateDependenciesTrait.php b/core/lib/Drupal/Core/DependencyInjection/UpdateDependenciesTrait.php
index 8cbc70c..c7e706f 100644
--- a/core/lib/Drupal/Core/DependencyInjection/UpdateDependenciesTrait.php
+++ b/core/lib/Drupal/Core/DependencyInjection/UpdateDependenciesTrait.php
@@ -15,6 +15,9 @@
  * Classes which trigger a container rebuild should point to the instances of
  * the services with the new container. Calling the ::updateDependencies()
  * method takes care of that.
+ *
+ * If the service depends on container parameters and if they can possibly
+ * change then the service will need to handle this itself.
  */
 trait UpdateDependenciesTrait {
 
diff --git a/core/tests/Drupal/Tests/Core/DependencyInjection/UpdateDependenciesTraitTest.php b/core/tests/Drupal/Tests/Core/DependencyInjection/UpdateDependenciesTraitTest.php
index 8050d2b..d25405b 100644
--- a/core/tests/Drupal/Tests/Core/DependencyInjection/UpdateDependenciesTraitTest.php
+++ b/core/tests/Drupal/Tests/Core/DependencyInjection/UpdateDependenciesTraitTest.php
@@ -43,4 +43,5 @@ public function testUpdateDependencies() {
     $this->assertSame($container, $trait->container);
     $this->assertSame($object, $trait->object);
   }
+
 }