diff --git a/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php b/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
index 33f9db3..132048c 100644
--- a/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
+++ b/core/lib/Drupal/Core/TypedData/DataDefinitionInterface.php
@@ -62,7 +62,10 @@ public function getDataType();
   /**
    * Returns a human readable label.
    *
-   * @return string
+   * String or an instance of TranslatableMarkup based on the way how the label
+   * translation is handled.
+   *
+   * @return string|\Drupal\Core\StringTranslation\TranslatableMarkup
    *   The label.
    */
   public function getLabel();