diff --git a/nebula.nix b/nebula.nix
index 6b0a57a..fc9b27c 100644
--- a/nebula.nix
+++ b/nebula.nix
@@ -9,4 +9,7 @@
     key = "/var/lib/nebula/node.key";
     ca = "/var/lib/nebula/ca.crt";
   };
+
+  networking.firewall.allowedTCPPorts = [ 4242 ];
+  networking.firewall.allowedUDPPorts = [ 4242 ];
 }