diff --git a/pkgs/tools/security/zeekscript/default.nix b/pkgs/tools/security/zeekscript/default.nix
index c9f06596adc2..eb7d097c5d74 100644
--- a/pkgs/tools/security/zeekscript/default.nix
+++ b/pkgs/tools/security/zeekscript/default.nix
@@ -6,7 +6,7 @@
 python3.pkgs.buildPythonApplication rec {
   pname = "zeekscript";
   version = "1.2.8";
-  format = "pyproject";
+  pyproject = true;
 
   src = fetchPypi {
     inherit pname version;