diff --git a/bb2etp/__init__.py b/bb2etp/src/__init__.py
similarity index 100%
rename from bb2etp/__init__.py
rename to bb2etp/src/__init__.py
diff --git a/bb2etp/core.py b/bb2etp/src/core.py
similarity index 100%
rename from bb2etp/core.py
rename to bb2etp/src/core.py
diff --git a/pyproject.toml b/pyproject.toml
index 4cea500446c3b3c7cae4a8a4380c9007f23427c7..0c6ce7bc4901fa980bfd689543c45742b5c3de45 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools>=42", "wheel"]
+requires = ["setuptools", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [project]