diff --git a/pkgs/development/python-modules/pystemd/default.nix b/pkgs/development/python-modules/pystemd/default.nix
index 6787c0a89782..44251a333ed9 100644
--- a/pkgs/development/python-modules/pystemd/default.nix
+++ b/pkgs/development/python-modules/pystemd/default.nix
@@ -25,7 +25,9 @@ buildPythonPackage rec {
 
   nativeBuildInputs = [ pkg-config ];
 
-  nativeCheckInputs = [ lxml mock psutil pytest ];
+  propagatedBuildInputs = [ lxml psutil ];
+
+  nativeCheckInputs = [ mock pytest ];
 
   checkPhase = "pytest tests";