diff --git a/interface/lib/classes/validate_dns.inc.php b/interface/lib/classes/validate_dns.inc.php
index 345396fbba39f0c622af96e869f8f6c57ffc0ec1..c4b94b5f7765d02a2e5715cc97d88e320e83c049 100644
--- a/interface/lib/classes/validate_dns.inc.php
+++ b/interface/lib/classes/validate_dns.inc.php
@@ -306,7 +306,7 @@ class validate_dns {
 			foreach($field_value_array as $field_value) {
 				// Check if the IP is valid without range
 				$subnet = '';
-				$ip = $field_value;
+				$ip = trim($field_value);
 				if(strpos($ip, '/') !== false) {
 					list($ip, $subnet) = explode('/', $ip, 2);
 					$ip = trim($ip);