diff --git a/pyproject.toml b/pyproject.toml
index 65aa24a..a7663fa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,7 +17,7 @@ dependencies = [
 Homepage = "https://github.com/jazzband/django-fernet-encrypted-fields/"
 
 [build-system]
-requires = ["setuptools"]
+requires = ["setuptools>=61.0.0"]
 build-backend = "setuptools.build_meta"
 
 
@@ -30,7 +30,7 @@ lint.fixable = ["ALL"]
 lint.ignore = ["A003", "COM812", "D", "DJ008", "ERA001", "ISC001", "PLC2401", "PLC2403", "PT011", "RUF001", "S101", "S105", "S608", "SIM103", "TC001", "TC002", "TC003", "UP040"]
 lint.select = ["ALL"]
 lint.unfixable = ["ERA001", "F401"]
-include = ["encrypted_fields/*.py", "package_test/*.py"]
+extend-include = ["package_test/**/*.py"]
 target-version = "py312"
 
 ##################
diff --git a/encrypted_fields/__init__.py b/src/encrypted_fields/__init__.py
similarity index 100%
rename from encrypted_fields/__init__.py
rename to src/encrypted_fields/__init__.py
diff --git a/encrypted_fields/fields.py b/src/encrypted_fields/fields.py
similarity index 100%
rename from encrypted_fields/fields.py
rename to src/encrypted_fields/fields.py