diff --git a/nixos/modules/monitoring/vpn/client.nix b/nixos/modules/monitoring/vpn/client.nix
index 8c443321a30ff4c712e3dbba8db0faad5c281973..9c204743ae731558043118e798a0b6737e5d77c5 100644
--- a/nixos/modules/monitoring/vpn/client.nix
+++ b/nixos/modules/monitoring/vpn/client.nix
@@ -77,6 +77,7 @@ in {
           endpoint = cfg.client.endpoint;  # meaning: the server.
           publicKey = builtins.readFile(cfg.client.endpointPublicKeyFile);
           presharedKeyFile = toString cfg.client.presharedKeyFile;
+          persistentKeepalive = 25;
         }
       ];
     };