diff --git a/src/wp-includes/class-wp-locale.php b/src/wp-includes/class-wp-locale.php
index 81a80a59f0..287914e880 100644
--- a/src/wp-includes/class-wp-locale.php
+++ b/src/wp-includes/class-wp-locale.php
@@ -43,14 +43,6 @@ class WP_Locale {
 	 */
 	public $weekday_abbrev;
 
-	/**
-	 * Stores the default start of the week.
-	 *
-	 * @since 4.4.0
-	 * @var string
-	 */
-	public $start_of_week;
-
 	/**
 	 * Stores the translated strings for the full month names.
 	 *