diff --git a/pkgs/development/python-modules/typeguard/default.nix b/pkgs/development/python-modules/typeguard/default.nix
index 4873e61061da..4f74f088f82d 100644
--- a/pkgs/development/python-modules/typeguard/default.nix
+++ b/pkgs/development/python-modules/typeguard/default.nix
@@ -53,6 +53,10 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
+  # To prevent test from writing out non-reproducible .pyc files
+  # https://github.com/agronholm/typeguard/blob/ca512c28132999da514f31b5e93ed2f294ca8f77/tests/test_typechecked.py#L641
+  preCheck = "export PYTHONDONTWRITEBYTECODE=1";
+
   pythonImportsCheck = [ "typeguard" ];
 
   meta = {