diff --git a/hosts/thrall/default.nix b/hosts/thrall/default.nix
index 3da635c..c2934c8 100644
--- a/hosts/thrall/default.nix
+++ b/hosts/thrall/default.nix
@@ -84,6 +84,7 @@ in
           80
           443
           5000
+          40005 # syncthing
         ];
         allowedUDPPorts = [
           53