diff --git a/server/lib/classes/monitor_tools.inc.php b/server/lib/classes/monitor_tools.inc.php
index 6539a1ae4a4861e965ea0eb74d00510e107acfd7..a9bdaed7b45e644472270e070e2b9ea66bb4d759 100644
--- a/server/lib/classes/monitor_tools.inc.php
+++ b/server/lib/classes/monitor_tools.inc.php
@@ -597,7 +597,7 @@ class monitor_tools {
 		/* Monitor BIND-Server */
 		$data['bindserver'] = -1; // unknown - not needed
 		if ($services['dns_server'] == 1) {
-			if ($this->_checkTcp('localhost', 53)) {
+			if ($this->_checkUdp('localhost', 53)) {
 				$data['bindserver'] = 1;
 			} else {
 				$data['bindserver'] = 0;