diff --git a/hosts/radius/configuration.nix b/hosts/radius/configuration.nix
index e19447d..36d6db3 100644
--- a/hosts/radius/configuration.nix
+++ b/hosts/radius/configuration.nix
@@ -30,5 +30,7 @@ with lib;
   users.users.radius.group = "radius";
   users.groups.radius = {};
 
+  networking.firewall.allowedUDPPorts = [ 1812 ];
+
   system.stateVersion = "22.05";
 }