diff --git a/src/wp-admin/includes/screen.php b/src/wp-admin/includes/screen.php
index 0bbffc04f7..3c6a5131b9 100644
--- a/src/wp-admin/includes/screen.php
+++ b/src/wp-admin/includes/screen.php
@@ -200,7 +200,7 @@ function add_screen_option( $option, $args = array() ) {
  *
  * @global WP_Screen $current_screen
  *
- * @return WP_Screen Current screen object
+ * @return WP_Screen|null Current screen object or null when screen not defined.
  */
 function get_current_screen() {
 	global $current_screen;