diff --git a/lam/lib/checkEnvironment.inc b/lam/lib/checkEnvironment.inc
index 3a50358e..e8bc26ff 100644
--- a/lam/lib/checkEnvironment.inc
+++ b/lam/lib/checkEnvironment.inc
@@ -2,7 +2,7 @@
 /*
 
   This code is part of LDAP Account Manager (http://www.ldap-account-manager.org/)
-  Copyright (C) 2010 - 2018  Roland Gruber
+  Copyright (C) 2010 - 2019  Roland Gruber
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -81,6 +81,12 @@ if (! function_exists('utf8_decode') || !extension_loaded('xml')) {
 if (!extension_loaded('libxml')) {
 	$criticalErrors[] = array("ERROR", "Your PHP has no Lib XML support!", "Please install the Lib XML extension for PHP.");
 }
+if (!class_exists('XMLReader')) {
+	$criticalErrors[] = array("ERROR", "Your PHP has no XMLReader support!", "Please active XMLReader for PHP.");
+}
+if (!class_exists('XMLWriter')) {
+	$criticalErrors[] = array("ERROR", "Your PHP has no XMLWriter support!", "Please active XMLWriter for PHP.");
+}
 // imagick/GD
 if (!extension_loaded('imagick') && !function_exists('getimagesize')) {
 	$criticalErrors[] = array("ERROR", "Your PHP has no imagick or GD support.", "Please install the imagick or GD extension for PHP.");