diff --git a/src/wp-includes/class-wp-theme.php b/src/wp-includes/class-wp-theme.php
index 7471b506bb..1fbe16d562 100644
--- a/src/wp-includes/class-wp-theme.php
+++ b/src/wp-includes/class-wp-theme.php
@@ -1361,7 +1361,10 @@ final class WP_Theme implements ArrayAccess {
 	 * @static
 	 * @access private
 	 *
-	 * @return int
+	 * @param string $a First name.
+	 * @param string $b Second name.
+	 * @return int Negative if `$a` falls lower in the natural order than `$b`. Zero if they fall equally.
+	 *             Greater than 0 if `$a` falls higher in the natural order than `$b`. Used with uasort().
 	 */
 	private static function _name_sort_i18n( $a, $b ) {
 		// Don't mark up; Do translate.