diff --git a/hosts/bicep/services/matrix/smtp-authenticator/default.nix b/hosts/bicep/services/matrix/smtp-authenticator/default.nix
index d4cfebc..d8a7000 100644
--- a/hosts/bicep/services/matrix/smtp-authenticator/default.nix
+++ b/hosts/bicep/services/matrix/smtp-authenticator/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildPythonPackage, fetchFromGitHub }:
+{ lib, buildPythonPackage, fetchFromGitHub, setuptools }:
 
 buildPythonPackage rec {
   pname = "matrix-synapse-smtp-auth";
@@ -6,6 +6,9 @@ buildPythonPackage rec {
 
   src = ./.;
 
+  pyproject = true;
+  build-system = [ setuptools ];
+
   doCheck = false;
 
   meta = with lib; {