diff --git a/nix/deuxfleurs.nix b/nix/deuxfleurs.nix
index 5e87e5d..e2c1c17 100644
--- a/nix/deuxfleurs.nix
+++ b/nix/deuxfleurs.nix
@@ -214,6 +214,7 @@ in
       address = [ "${cfg.cluster_ip}/16" ];
       listenPort = cfg.wireguard_port;
       privateKeyFile = "/var/lib/deuxfleurs/wireguard-keys/private";
+      mtu = 1420;
       peers = map ({ publicKey, endpoint, IP, site_name, lan_endpoint, ... }: {
         publicKey = publicKey;
         allowedIPs = [ "${IP}/32" ];