diff --git a/core/lib/Drupal/Core/Cache/RuntimeCacheableDependencyInterface.php b/core/lib/Drupal/Core/Cache/MutableCacheableDependencyInterface.php
similarity index 18%
rename from core/lib/Drupal/Core/Cache/RuntimeCacheableDependencyInterface.php
rename to core/lib/Drupal/Core/Cache/MutableCacheableDependencyInterface.php
index 03d88d4..acfe5f6 100644
--- a/core/lib/Drupal/Core/Cache/RuntimeCacheableDependencyInterface.php
+++ b/core/lib/Drupal/Core/Cache/MutableCacheableDependencyInterface.php
@@ -1,41 +1,51 @@
 <?php
-
 /**
  * @file
- * Contains \Drupal\Core\Cache\RuntimeCacheableDependencyInterface.
+ * Contains \Drupal\Core\Cache\MutableCacheableDependencyInterface.
  */
 
 namespace Drupal\Core\Cache;
 
 /**
- * Interface for objects that can change cache dependencies during runtime.
+ * Allows to add cacheability metadata to an object for the current runtime.
  *
- * @ingroup cache
+ * This must be used when changing an object in a way that affects its
+ * cacheability. For example, when changing the active translation of an entity
+ * based on the current content language then a cache context for that must be
+ * added.
  */
-interface RuntimeCacheableDependencyInterface {
+interface MutableCacheableDependencyInterface extends CacheableDependencyInterface {
 
   /**
-   * Adds cache contexts during runtime.
+   * Adds cache contexts.
    *
    * @param string[] $cache_contexts
-   *   An array of cache context tokens to add.
+   *   The cache contexts to be added.
+   *
+   * @return $this
    */
-  public function addRuntimeCacheContexts(array $cache_contexts);
+  public function addCacheContexts(array $cache_contexts);
 
   /**
-   * Adds cache tags during runtime.
+   * Adds cache tags.
    *
    * @param string[] $cache_tags
-   *   An array of cache tags to add.
+   *   The cache tags to be added.
+   *
+   * @return $this
    */
-  public function addRuntimeCacheTags(array $cache_tags);
+  public function addCacheTags(array $cache_tags);
 
   /**
-   * Sets the cache max age during runtime.
+   * Sets the maximum age (in seconds).
+   *
+   * This only sets the max age if it is lower than the existing one.
    *
    * @param int $max_age
-   *   The cache max-age value.
+   *   The max age to associate.
+   *
+   * @return $this
    */
-  public function setRuntimeCacheMaxAge($max_age);
+  public function setCacheMaxAgeIfLower($max_age);
 
 }
diff --git a/core/lib/Drupal/Core/Cache/MutableCacheableDependencyTrait.php b/core/lib/Drupal/Core/Cache/MutableCacheableDependencyTrait.php
new file mode 100644
index 0000000..8d33b55
--- /dev/null
+++ b/core/lib/Drupal/Core/Cache/MutableCacheableDependencyTrait.php
@@ -0,0 +1,60 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Cache\MutableCacheableDependencyTrait.
+ */
+
+namespace Drupal\Core\Cache;
+
+/**
+ * Trait for \Drupal\Core\Cache\MutableCacheableDependencyInterface.
+ */
+trait MutableCacheableDependencyTrait {
+
+  /**
+   * Runtime cache contexts.
+   *
+   * @var array
+   */
+  protected $cacheContexts = [];
+
+  /**
+   * Cache tags.
+   *
+   * @var string[]
+   */
+  protected $cacheTags = [];
+
+  /**
+   * Cache max-age.
+   *
+   * @var int
+   */
+  protected $cacheMaxAge = Cache::PERMANENT;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addCacheContexts(array $cache_contexts) {
+    $this->cacheContexts = Cache::mergeContexts($this->cacheContexts, $cache_contexts);
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addCacheTags(array $cache_tags) {
+    $this->cacheTags = Cache::mergeTags($this->cacheTags, $cache_tags);
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setCacheMaxAgeIfLower($max_age) {
+    $this->cacheMaxAge = Cache::mergeMaxAges($this->cacheMaxAge, $max_age);
+    return $this;
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Config/ConfigBase.php b/core/lib/Drupal/Core/Config/ConfigBase.php
index e88560e..51801b1 100644
--- a/core/lib/Drupal/Core/Config/ConfigBase.php
+++ b/core/lib/Drupal/Core/Config/ConfigBase.php
@@ -11,7 +11,8 @@
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Cache\CacheableDependencyInterface;
-use Drupal\Core\Cache\RuntimeCacheableDependencyInterface;
+use Drupal\Core\Cache\MutableCacheableDependencyInterface;
+use Drupal\Core\Cache\MutableCacheableDependencyTrait;
 use \Drupal\Core\DependencyInjection\DependencySerializationTrait;
 
 /**
@@ -29,8 +30,9 @@
  * @see \Drupal\Core\Config\Config
  * @see \Drupal\Core\Theme\ThemeSettings
  */
-abstract class ConfigBase implements CacheableDependencyInterface, RuntimeCacheableDependencyInterface {
+abstract class ConfigBase implements CacheableDependencyInterface, MutableCacheableDependencyInterface {
   use DependencySerializationTrait;
+  use MutableCacheableDependencyTrait;
 
   /**
    * The name of the configuration object.
@@ -47,27 +49,6 @@
   protected $data = array();
 
   /**
-   * The cache contexts this configuration object provides.
-   *
-   * @var string[]
-   */
-  protected $cacheContexts = [];
-
-  /**
-   * The cache tags this configuration object provides.
-   *
-   * @var string[]
-   */
-  protected $cacheTags = [];
-
-  /**
-   * The cache max age this configuration object provides.
-   *
-   * @var int
-   */
-  protected $cacheMaxAge = Cache::PERMANENT;
-
-  /**
    * The maximum length of a configuration object name.
    *
    * Many filesystems (including HFS, NTFS, and ext4) have a maximum file name
@@ -308,25 +289,4 @@ public function getCacheMaxAge() {
     return $this->cacheMaxAge;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function addRuntimeCacheContexts(array $cache_contexts) {
-    $this->cacheContexts = Cache::mergeContexts($this->cacheContexts, $cache_contexts);
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function addRuntimeCacheTags(array $cache_tags) {
-    $this->cacheTags = Cache::mergeTags($this->cacheTags, $cache_tags);
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function setRuntimeCacheMaxAge($max_age) {
-    $this->cacheMaxAge = Cache::mergeMaxAges($this->cacheMaxAge, $max_age);
-  }
-
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
index b295297..907ea6d 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -9,8 +9,6 @@
 
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Cache\Context\CacheContextInterface;
-use Drupal\Core\Cache\RuntimeCacheableDependencyInterface;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
@@ -227,9 +225,9 @@ protected function loadOverrides(array $names) {
    */
   protected function propagateCacheableDependencyOverrides($cache_key) {
     foreach ($this->configFactoryOverrides as $override) {
-      $this->cache[$cache_key]->addRuntimeCacheContexts($override->getCacheContexts());
-      $this->cache[$cache_key]->addRuntimeCacheTags($override->getCacheTags());
-      $this->cache[$cache_key]->setRuntimeCacheMaxAge($override->getCacheMaxAge());
+      $this->cache[$cache_key]->addCacheContexts($override->getCacheContexts());
+      $this->cache[$cache_key]->addCacheTags($override->getCacheTags());
+      $this->cache[$cache_key]->setCacheMaxAgeIfLower($override->getCacheMaxAge());
     }
   }