diff --git a/src/wp-includes/ms-functions.php b/src/wp-includes/ms-functions.php
index ee0544378e..2984eb5da7 100644
--- a/src/wp-includes/ms-functions.php
+++ b/src/wp-includes/ms-functions.php
@@ -2301,6 +2301,8 @@ function wp_update_network_counts( $network_id = null ) {
  *
  * @since 3.7.0
  * @since 4.8.0 The $network_id parameter has been added.
+ *
+ * @param int|null $network_id ID of the network. Default is the current network.
  */
 function wp_maybe_update_network_site_counts( $network_id = null ) {
 	$is_small_network = ! wp_is_large_network( 'sites', $network_id );