diff --git a/pyproject.toml b/pyproject.toml
index b336a5cb2..e7fdbca51 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,7 +47,9 @@ dependencies = {file = ["requirements/requirements.txt"]}
 
 [tool.setuptools]
 packages = ["elephant", "elephant.test"]
-
+ext-modules = [
+  {name = "elephant.spade_src.fim", sources = ["elephant/spade_src/src/fim.cpp"],include-dirs=["elephant/spade_src/include"],language="c++", extra-compile-args=["-DMODULE_NAME=fim", "-DUSE_OPENMP", "-DWITH_SIG_TERM","-Dfim_EXPORTS", "-fopenmp", "/std:c++17"], optional=true}
+]
 
 # This file was created following this guide:
 # https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#writing-pyproject-toml
diff --git a/setup.py b/setup_old.py
similarity index 100%
rename from setup.py
rename to setup_old.py