diff --git a/core/lib/Drupal/Core/Template/TwigExtension.php b/core/lib/Drupal/Core/Template/TwigExtension.php
index 778519a..7069f1c 100644
--- a/core/lib/Drupal/Core/Template/TwigExtension.php
+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -374,7 +374,7 @@ public function attachLibrary($library) {
    *   The escaped, rendered output, or NULL if there is no valid output.
    *
    * @throws \Exception
-   *   When the object cannot be printed.
+   *   When an object is passed that has no __toString method.
    */
   public function escapePlaceholder($env, $string) {
     return '<em class="placeholder">' . $this->escapeFilter($env, $string) . '</em>';
@@ -404,7 +404,7 @@ public function escapePlaceholder($env, $string) {
    *   The escaped, rendered output, or NULL if there is no valid output.
    *
    * @throws \Exception
-   *   When the object cannot be printed.
+   *   When an object is passed that has no __toString method.
    *
    * @todo Refactor this to keep it in sync with theme_render_and_autoescape()
    *   in https://www.drupal.org/node/2575065
@@ -490,7 +490,7 @@ public function escapeFilter(\Twig_Environment $env, $arg, $strategy = 'html', $
    *   The rendered output or an Twig_Markup object.
    *
    * @throws \Exception
-   *   When the object cannot be printed.
+   *   When an object is passed that has no __toString method.
    *
    * @see render
    * @see TwigNodeVisitor