diff --git a/src/etc/inc/interfaces.inc b/src/etc/inc/interfaces.inc
index 2f0287f11..3ad719f5b 100644
--- a/src/etc/inc/interfaces.inc
+++ b/src/etc/inc/interfaces.inc
@@ -1,7 +1,7 @@
 <?php
 
 /*
- * Copyright (C) 2015-2018 Franco Fichtner <franco@opnsense.org>
+ * Copyright (C) 2015-2020 Franco Fichtner <franco@opnsense.org>
  * Copyright (C) 2004-2008 Scott Ullrich <sullrich@gmail.com>
  * Copyright (C) 2008-2009 Ermal Luçi
  * Copyright (C) 2005 Espen Johansen
@@ -4579,3 +4579,34 @@ function interfaces_addresses($interfaces, $as_subnet = false, $ifconfig_details
 
     return $result;
 }
+
+function interfaces_primary_address6($interface, $realif = null, $ifconfig_details = null)
+{
+    $ifcfgipv6 = $networkv6 = null;
+
+    if ($realif === null) {
+        $realif = get_real_interface($interface, 'inet6');
+    }
+
+    foreach (interfaces_addresses($realif, true, $ifconfig_details) as $tmpaddr => $info) {
+        if ($info['family'] != 'inet6' || $info['scope']) {
+            /* only care about IPv6 without a scope set */
+            continue;
+        }
+
+        $addrparts = explode('/', $tmpaddr);
+
+        foreach (config_read_array('virtualip', 'vip') as $vip) {
+            if ($vip['interface'] == $interface && $vip['mode'] == 'ipalias' && $vip['subnet'] == $addrparts[0]) {
+                /* do not care about alias */
+                continue 2;
+            }
+        }
+
+        $networkv6 = gen_subnetv6($addrparts[0], $addrparts[1]) . "/{$addrparts[1]}";
+        $ifcfgipv6 = $addrparts[0];
+        break; /* all done */
+    }
+
+    return [ $ifcfgipv6, $networkv6 ];
+}
diff --git a/src/etc/inc/plugins.inc.d/dhcpd.inc b/src/etc/inc/plugins.inc.d/dhcpd.inc
index 492d5bb8f..108a1f124 100644
--- a/src/etc/inc/plugins.inc.d/dhcpd.inc
+++ b/src/etc/inc/plugins.inc.d/dhcpd.inc
@@ -302,7 +302,7 @@ function dhcpd_radvd_configure($verbose = false, $blacklist = array())
 
         $stanzas = array();
 
-        list ($ifcfgipv6, $networkv6) = dhcpd_getaddr6($dhcpv6if, $realif, $ifconfig_details);
+        list ($ifcfgipv6, $networkv6) = interfaces_primary_address6($dhcpv6if, $realif, $ifconfig_details);
         if (is_subnetv6($networkv6)) {
             $stanzas[] = $networkv6;
         }
@@ -454,7 +454,7 @@ function dhcpd_radvd_configure($verbose = false, $blacklist = array())
 
         $dnslist = array();
 
-        list ($ifcfgipv6, $networkv6) = dhcpd_getaddr6($if, $realif, $ifconfig_details);
+        list ($ifcfgipv6, $networkv6) = interfaces_primary_address6($if, $realif, $ifconfig_details);
 
         if ($autotype == 'slaac') {
             /* XXX this may be incorrect and needs an override or revisit */
@@ -1240,7 +1240,7 @@ function dhcpd_dhcp6_configure($verbose = false, $blacklist = array())
             continue;
         }
         if (!empty($config['interfaces'][$ifname]['track6-interface'])) {
-            list ($ifcfgipv6) = dhcpd_getaddr6($ifname, null, $ifconfig_details);
+            list ($ifcfgipv6) = interfaces_primary_address6($ifname, null, $ifconfig_details);
             if (!is_ipaddrv6($ifcfgipv6)) {
                 continue;
             }
@@ -1392,7 +1392,7 @@ EOD;
             continue;
         }
 
-        list ($ifcfgipv6, $networkv6) = dhcpd_getaddr6($dhcpv6if, null, $ifconfig_details);
+        list ($ifcfgipv6, $networkv6) = interfaces_primary_address6($dhcpv6if, null, $ifconfig_details);
         if (!is_ipaddrv6($ifcfgipv6) || !is_subnetv6($networkv6)) {
             log_error("Warning! dhcpd_dhcp6_configure() found no suitable IPv6 address on {$dhcpv6if}");
             continue;
@@ -1829,34 +1829,3 @@ function dhcpd_dhcrelay6_configure($verbose = false)
         echo "done.\n";
     }
 }
-
-function dhcpd_getaddr6($interface, $realif = null, $ifconfig_details = null)
-{
-    $ifcfgipv6 = $networkv6 = null;
-
-    if ($realif === null) {
-        $realif = get_real_interface($interface, 'inet6');
-    }
-
-    foreach (interfaces_addresses($realif, true, $ifconfig_details) as $tmpaddr => $info) {
-        if ($info['family'] != 'inet6' || $info['scope']) {
-            /* only care about IPv6 without a scope set */
-            continue;
-        }
-
-        $addrparts = explode('/', $tmpaddr);
-
-        foreach (config_read_array('virtualip', 'vip') as $vip) {
-            if ($vip['interface'] == $interface && $vip['mode'] == 'ipalias' && $vip['subnet'] == $addrparts[0]) {
-                /* do not care about alias */
-                continue 2;
-            }
-        }
-
-        $networkv6 = gen_subnetv6($addrparts[0], $addrparts[1]) . "/{$addrparts[1]}";
-        $ifcfgipv6 = $addrparts[0];
-        break; /* all done */
-    }
-
-    return [ $ifcfgipv6, $networkv6 ];
-}
diff --git a/src/www/services_dhcpv6.php b/src/www/services_dhcpv6.php
index fce52918d..9325baf4a 100644
--- a/src/www/services_dhcpv6.php
+++ b/src/www/services_dhcpv6.php
@@ -321,7 +321,7 @@ legacy_html_escape_form_data($pconfig);
 
 include("head.inc");
 
-list ($wifcfgip, $networkv6) = dhcpd_getaddr6($if);
+list ($wifcfgip, $networkv6) = interfaces_primary_address6($if);
 $wifcfgsn = explode('/', $networkv6)[1];
 
 if (isset($config['interfaces'][$if]['dhcpd6track6allowoverride'])) {