diff --git a/nixos/modules/services/network-filesystems/tahoe.nix b/nixos/modules/services/network-filesystems/tahoe.nix
index 1176fb3131fc..3297e65dac2b 100644
--- a/nixos/modules/services/network-filesystems/tahoe.nix
+++ b/nixos/modules/services/network-filesystems/tahoe.nix
@@ -140,7 +140,7 @@ in
             sftpd.enable = lib.mkEnableOption "SFTP service";
             sftpd.port = lib.mkOption {
               default = null;
-              type = lib.types.nullOr lib.types.int;
+              type = lib.types.nullOr lib.types.port;
               description = ''
                 The port on which the SFTP server will listen.