diff --git a/pkgs/development/python-modules/os-service-types/tests.nix b/pkgs/development/python-modules/os-service-types/tests.nix
index 5958d824d58d..a0996765cb6b 100644
--- a/pkgs/development/python-modules/os-service-types/tests.nix
+++ b/pkgs/development/python-modules/os-service-types/tests.nix
@@ -7,11 +7,10 @@
 , testscenarios
 }:
 
-buildPythonPackage rec {
+buildPythonPackage {
   pname = "os-service-types-tests";
-  inherit (os-service-types) version;
-
-  src = os-service-types.src;
+  inherit (os-service-types) version src;
+  format = "other";
 
   postPatch = ''
     # only a small portion of the listed packages are actually needed for running the tests