diff --git a/core/lib/Drupal/Core/Cache/UncacheableDependencyTrait.php b/core/lib/Drupal/Core/Cache/UncacheableDependencyTrait.php
index a2f00e8..ee624fc 100644
--- a/core/lib/Drupal/Core/Cache/UncacheableDependencyTrait.php
+++ b/core/lib/Drupal/Core/Cache/UncacheableDependencyTrait.php
@@ -10,7 +10,8 @@
 /**
  * Trait to implement CacheableDependencyInterface for uncacheable objects.
  *
- * Use this for objects that are never cacheable.
+ * Use this for objects that are never cacheable. Because the max-age is
+ * unconditionally zero, we don't care about the cache tags or contexts.
  *
  * @see \Drupal\Core\Cache\CacheableDependencyInterface
  */