diff --git a/src/opnsense/mvc/app/controllers/OPNsense/Firewall/Api/AliasController.php b/src/opnsense/mvc/app/controllers/OPNsense/Firewall/Api/AliasController.php
index 4fc17445d..b54e7266d 100644
--- a/src/opnsense/mvc/app/controllers/OPNsense/Firewall/Api/AliasController.php
+++ b/src/opnsense/mvc/app/controllers/OPNsense/Firewall/Api/AliasController.php
@@ -109,10 +109,11 @@ class AliasController extends ApiMutableModelControllerBase
         $response = $this->getBase("alias", "aliases.alias", $uuid);
         $selected_aliases = array_keys($response['alias']['content']);
         foreach ($this->getModel()->aliasIterator() as $alias) {
-            if (!in_array($alias['name'], $selected_aliases)) {
-                $response['alias']['content'][$alias['name']] = array(
+            // external aliases can't be nested (always empty according to our administration)
+            if (!in_array($alias['name'], $selected_aliases) && $alias['type'] != "external") {
+                $response['alias']['content'][$alias['name']] = [
                   "selected" => 0, "value" => $alias['name']
-                );
+                ];
             }
         }
         return $response;