diff --git a/wp-admin/admin-ajax.php b/wp-admin/admin-ajax.php
index b6420e22b5..b795180011 100644
--- a/wp-admin/admin-ajax.php
+++ b/wp-admin/admin-ajax.php
@@ -57,6 +57,9 @@ case 'fetch-list' :
 	$current_screen->is_network = 'false' === $current_screen->is_network ? false : true;
 	$current_screen->is_user = 'false' === $current_screen->is_user ? false : true;
 
+	define( 'WP_NETWORK_ADMIN', $current_screen->is_network );
+	define( 'WP_USER_ADMIN', $current_screen->is_user );
+
 	$wp_list_table = get_list_table( $_GET['list_args']['class'] );
 	if ( ! $wp_list_table )
 		die( '0' );
diff --git a/wp-includes/load.php b/wp-includes/load.php
index 96845facf9..a384f1e3de 100644
--- a/wp-includes/load.php
+++ b/wp-includes/load.php
@@ -610,11 +610,6 @@ function is_blog_admin() {
  * @return bool True if inside WordPress network administration pages.
  */
 function is_network_admin() {
-	if ( defined('DOING_AJAX') && function_exists('get_current_screen') ) {
-		$screen = get_current_screen();
-		return (bool) $screen->is_network;
-	}
-
 	if ( defined( 'WP_NETWORK_ADMIN' ) )
 		return WP_NETWORK_ADMIN;
 	return false;