diff --git a/pkgs/development/python-modules/axisregistry/default.nix b/pkgs/development/python-modules/axisregistry/default.nix
index f4760c620076..e0379c127e6c 100644
--- a/pkgs/development/python-modules/axisregistry/default.nix
+++ b/pkgs/development/python-modules/axisregistry/default.nix
@@ -5,8 +5,8 @@
   fonttools,
   protobuf,
   pytestCheckHook,
-  setuptools-scm,
   pythonOlder,
+  setuptools-scm,
 }:
 
 buildPythonPackage rec {
@@ -27,6 +27,8 @@ buildPythonPackage rec {
   # in the closure of fontbakery. It seems to be compatible enough.
   pythonRelaxDeps = [ "protobuf" ];
 
+  env.PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION = "python";
+
   build-system = [ setuptools-scm ];
 
   dependencies = [