diff --git a/src/opnsense/mvc/app/models/OPNsense/Firewall/FieldTypes/AliasContentField.php b/src/opnsense/mvc/app/models/OPNsense/Firewall/FieldTypes/AliasContentField.php
index ac2e1b8af..b71ceadd5 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Firewall/FieldTypes/AliasContentField.php
+++ b/src/opnsense/mvc/app/models/OPNsense/Firewall/FieldTypes/AliasContentField.php
@@ -1,31 +1,29 @@
 <?php
 
-/**
- *    Copyright (C) 2018 Deciso B.V.
+/*
+ * Copyright (C) 2018-2022 Deciso B.V.
+ * All rights reserved.
  *
- *    All rights reserved.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
  *
- *    Redistribution and use in source and binary forms, with or without
- *    modification, are permitted provided that the following conditions are met:
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
  *
- *    1. Redistributions of source code must retain the above copyright notice,
- *       this list of conditions and the following disclaimer.
- *
- *    2. Redistributions in binary form must reproduce the above copyright
- *       notice, this list of conditions and the following disclaimer in the
- *       documentation and/or other materials provided with the distribution.
- *
- *    THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
- *    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
- *    AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- *    AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
- *    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- *    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- *    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- *    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- *    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- *    POSSIBILITY OF SUCH DAMAGE.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
  *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
  */
 
 namespace OPNsense\Firewall\FieldTypes;
@@ -147,12 +145,16 @@ class AliasContentField extends BaseField
     {
         $messages = array();
         foreach ($this->getItems($data) as $host) {
-            if (strpos($host, "!") === 0 && Util::isIpAddress(substr($host, 1))) {
+            $range = explode('-', $host);
+            if (count($range) == 2 && Util::isIpAddress($range[0]) && Util::isIpAddress($range[1])) {
+                // address range
+                continue;
+            } elseif (strpos($host, '!') === 0 && Util::isIpAddress(substr($host, 1))) {
                 // exclude address (https://www.freebsd.org/doc/handbook/firewalls-pf.html 30.3.2.4)
                 continue;
             } elseif (!Util::isAlias($host) && !Util::isIpAddress($host) && !Util::isDomain($host)) {
                 $messages[] = sprintf(
-                    gettext('Entry "%s" is not a valid hostname or IP address.'),
+                    gettext('Entry "%s" is not a valid hostname, IP address or range.'),
                     $host
                 );
             }