diff --git a/src/I18n/DateFormatTrait.php b/src/I18n/DateFormatTrait.php
index 9fc64116e53..f76c658a99f 100644
--- a/src/I18n/DateFormatTrait.php
+++ b/src/I18n/DateFormatTrait.php
@@ -60,7 +60,7 @@ trait DateFormatTrait
     /**
      * Caches whether or not this class is a subclass of a Date or MutableDate
      *
-     * @var boolean
+     * @var bool
      */
     protected static $_isDateInstance;