diff --git a/core/lib/Drupal/Core/Field/FieldStorageDefinitionInterface.php b/core/lib/Drupal/Core/Field/FieldStorageDefinitionInterface.php
index d75eb2295b2f4ba43f7e11dd149f6da31684785d..ead716800865c4d101c951eee233a00fca827d6a 100644
--- a/core/lib/Drupal/Core/Field/FieldStorageDefinitionInterface.php
+++ b/core/lib/Drupal/Core/Field/FieldStorageDefinitionInterface.php
@@ -74,7 +74,7 @@ public function getSettings();
    *   The setting name.
    *
    * @return mixed
-   *   The setting value.
+   *   The setting value or NULL if the setting name doesn't exist.
    */
   public function getSetting($setting_name);
 
diff --git a/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php b/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
index e5614d3d462e85e092f7fad8a2f43654463b4a6f..3b9c64f4337aa5c0460e31b20f761fb0a60aaa79 100644
--- a/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
+++ b/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
@@ -143,7 +143,7 @@ public function getSettings();
    *   The setting name.
    *
    * @return mixed
-   *   The setting value.
+   *   The setting value or NULL if the setting name doesn't exist.
    */
   public function getSetting($setting_name);