diff --git a/src/wp-admin/includes/class-wp-plugin-install-list-table.php b/src/wp-admin/includes/class-wp-plugin-install-list-table.php
index e19d7f4184..69f8aa2840 100644
--- a/src/wp-admin/includes/class-wp-plugin-install-list-table.php
+++ b/src/wp-admin/includes/class-wp-plugin-install-list-table.php
@@ -13,6 +13,8 @@ class WP_Plugin_Install_List_Table extends WP_List_Table {
 	public $orderby = null;
 	public $groups = array();
 
+	private $error;
+
 	public function ajax_user_can() {
 		return current_user_can('install_plugins');
 	}