diff --git a/pkgs/development/python-modules/approvaltests/default.nix b/pkgs/development/python-modules/approvaltests/default.nix
index 5c91f2217155..60ba742323c7 100644
--- a/pkgs/development/python-modules/approvaltests/default.nix
+++ b/pkgs/development/python-modules/approvaltests/default.nix
@@ -33,6 +33,8 @@ buildPythonPackage rec {
   postPatch = ''
     test -f setup.py || mv setup/setup.approvaltests.py setup.py
 
+    python3 setup/set_version.py '${version}'
+
     patchShebangs internal_documentation/scripts
   '';