diff --git a/pkgs/development/python-modules/formbox/default.nix b/pkgs/development/python-modules/formbox/default.nix
index 387ee2bea4e..098d13e87c9 100644
--- a/pkgs/development/python-modules/formbox/default.nix
+++ b/pkgs/development/python-modules/formbox/default.nix
@@ -1,9 +1,9 @@
-{ lib, buildPythonPackage, pythonOlder, fetchFromSourcehut, bleach, markdown }:
+{ lib, buildPythonPackage, pythonOlder, fetchFromSourcehut, flit-core, bleach, markdown }:
 
 buildPythonPackage rec {
   pname = "formbox";
   version = "0.4.1";
-  format = "flit";
+  format = "pyproject";
   disabled = pythonOlder "3.6";
 
   src = fetchFromSourcehut {
@@ -13,6 +13,7 @@ buildPythonPackage rec {
     hash = "sha256-zOvXmSeBiwc0Z5mRMwMsHLU3A/iP7rpjXm0T0I2gUTk=";
   };
 
+  nativeBuildInputs = [ flit-core ];
   propagatedBuildInputs = [ bleach markdown ];
   doCheck = false; # there's no test
   pythonImportsCheck = [ "formbox" ];