diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 47a259b..3a2c0d4 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -341,7 +341,7 @@ function format_string($string, array $args) {
  * @param $text
  *   The text to check.
  *
- * @return boolean
+ * @return bool
  *   TRUE if the text is valid UTF-8, FALSE if not.
  *
  * @see \Drupal\Component\Utility\Unicode::validateUtf8()