diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 93adead..6c7a85c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,18 +9,18 @@ on:
 
 jobs:
   build_and_test:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.8, 3.9, '3.10', 3.11]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v3
         with:
           python-version: ${{ matrix.python-version }}
       - name: install dependencies
-        run: pip install cython numpy
+        run: pip install cython numpy wheel
       - name: build
         run: pip install $GITHUB_WORKSPACE
       - name: test
diff --git a/.github/workflows/wheels.yml b/.github/workflows/wheels.yml
index b4622a4..ffee56a 100644
--- a/.github/workflows/wheels.yml
+++ b/.github/workflows/wheels.yml
@@ -6,12 +6,14 @@ on:
 
 jobs:
   build_wheels:
-    name: Build wheels
-    runs-on: ubuntu-latest
-
+    name: Build wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-22.04, windows-2022]
+  
     steps:
       - uses: actions/checkout@v2
-
       - uses: actions/setup-python@v2
 
       - name: Install cibuildwheel
@@ -24,7 +26,7 @@ jobs:
           CIBW_BUILD: "{cp,pp}3*-*"
           CIBW_SKIP: "cp35-* *-manylinux_i686"
 
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v3
         with:
           path: ./wheelhouse/*.whl
 
@@ -45,7 +47,7 @@ jobs:
       - name: Build sdist
         run: python setup.py sdist
 
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v3
         with:
           path: dist/*.tar.gz
 
@@ -54,12 +56,14 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name == 'release' && github.event.action == 'published'
     steps:
-      - uses: actions/download-artifact@v2
+      - uses: actions/download-artifact@v3
         with:
           name: artifact
           path: dist
 
       - uses: pypa/gh-action-pypi-publish@master
         with:
-          user: __token__
-          password: ${{ secrets.PYPI_API_TOKEN }}
+          password: ${{ secrets.TEST_PYPI_API_TOKEN }}
+          repository-url: https://test.pypi.org/legacy/
+          #user: __token__
+          #password: ${{ secrets.PYPI_API_TOKEN }}
diff --git a/_version/__init__.py b/_version/__init__.py
deleted file mode 100644
index 63ecbb5..0000000
--- a/_version/__init__.py
+++ /dev/null
@@ -1,22 +0,0 @@
-"""
-_version
-
-Version information for MODAPE whittaker core
-
-"""
-
-__all__ = [
-    'VERSION_MAJOR',
-    'VERSION_MINOR',
-    'VERSION_PATCH',
-    'VERSION_STRING',
-    '__version__',
-]
-
-VERSION_MAJOR = 2
-VERSION_MINOR = 0
-VERSION_PATCH = 2
-
-VERSION_STRING = '%s.%s.%s' % (VERSION_MAJOR, VERSION_MINOR, VERSION_PATCH)
-
-__version__ = VERSION_STRING
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..e4ca2ec
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,3 @@
+[build-system]
+requires = ["setuptools>=51.0.0", "wheel", "numpy>=1.15.1", "cython"]
+build-backend = "setuptools.build_meta"
diff --git a/setup.cfg b/setup.cfg
index 18fa5e2..043f12a 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,3 +1,37 @@
+[metadata]
+name = vam.whittaker
+description = VAM whittaker core
+version = attr: vam.whittaker._version.__version__
+author = WFP-VAM
+author_email =
+maintainer = WFP-VAM
+maintainer_email =
+long_description_content_type = text/rst
+long_description = file: README.rst
+platforms = any
+license = MIT License
+url = http://github.com/WFP-VAM/vam.whittaker/
+project_urls =
+   Bug Reporting = http://github.com/WFP-VAM/vam.whittaker/issues
+
+classifiers =
+    License :: OSI Approved :: MIT License
+    Intended Audience :: Developers
+    Development Status :: 3 - Beta
+    Operating System :: OS Independent
+    Programming Language :: Python :: 3
+    Natural Language :: English
+    Topic :: Software Development :: Libraries :: Python Modules
+    Topic :: Scientific/Engineering :: GIS
+
+[options]
+python_requires = >=3,<4
+
+
+[options.packages.find]
+include =
+  vam*
+
 [aliases]
 test=pytest
 
diff --git a/setup.py b/setup.py
index 43994ab..854f838 100644
--- a/setup.py
+++ b/setup.py
@@ -1,20 +1,20 @@
-#!/usr/bin/env python
 # pylint: disable=invalid-name, line-too-long
 """setup.py for VAM whittaker core"""
 
 from setuptools import setup, Extension
 
 import numpy
-import _version
-USE_CYTHON = 'auto'
+
+USE_CYTHON = True  # "auto"
 
 if USE_CYTHON:
     try:
         from Cython.Distutils import build_ext
-        if USE_CYTHON == 'auto':
+
+        if USE_CYTHON == "auto":
             USE_CYTHON = True
     except ImportError:
-        if USE_CYTHON == 'auto':
+        if USE_CYTHON == "auto":
             USE_CYTHON = False
         else:
             raise
@@ -24,34 +24,28 @@
 
 if USE_CYTHON:
     ext_modules += [
-        Extension("vam.whittaker",
-                  ["src/_whittaker.pyx"], extra_compile_args=["-O3", "-ffast-math"])]
-    cmdclass.update({'build_ext': build_ext})
+        Extension(
+            "vam.whittaker._whit",
+            ["vam/whittaker/_whittaker.pyx"],
+            extra_compile_args=["-O3", "-ffast-math"],
+        )
+    ]
+    cmdclass.update({"build_ext": build_ext})
 else:
     ext_modules += [
-        Extension("vam.whittaker",
-                  ["src/_whittaker.c"], extra_compile_args=["-O3", "-ffast-math"])]
+        Extension(
+            "vam.whittaker._whit",
+            ["vam/whittaker/_whittaker.c"],
+            extra_compile_args=["-O3", "-ffast-math"],
+        )
+    ]
 
 setup(
-    name='vam.whittaker',
-    description='VAM whittaker core',
-    version=_version.__version__,
-    author='Valentin Pesendorfer',
-    author_email='valentin.pesendorfer@wfp.org',
-    url='http://github.com/WFP-VAM/vam.whittaker',
-    long_description='''State-of-the art whittaker smoother, implemented as fast C-extension through Cython and including a V-curve optimization of the smoothing parameter.\n\nFor more information, please visit: http://github.com/WFP-VAM/vam.whittaker''',
     include_dirs=[numpy.get_include()],
     cmdclass=cmdclass,
     ext_modules=ext_modules,
-    classifiers=[
-        'Development Status :: 4 - Beta',
-        'Programming Language :: Python :: 3',
-    ],
-    setup_requires=['pytest-runner'],
-    tests_require=['pytest'],
-    install_requires=[
-        'numpy>=1.15.1',
-        'mock;python_version<"3.0"'
-    ],
-    python_requires='>=3, <4',
+    setup_requires=["pytest-runner"],
+    tests_require=["pytest"],
+    install_requires=["numpy>=1.15.1", 'mock;python_version<"3.0"'],
+    python_requires=">=3, <4",
 )
diff --git a/vam/whittaker/__init__.py b/vam/whittaker/__init__.py
new file mode 100644
index 0000000..a26c4f5
--- /dev/null
+++ b/vam/whittaker/__init__.py
@@ -0,0 +1,4 @@
+from ._version import __version__
+from ._whit import lag1corr, ws2d, ws2dp, ws2doptv, ws2doptvp
+
+__all__ = ("__version__",)
diff --git a/vam/whittaker/_version.py b/vam/whittaker/_version.py
new file mode 100644
index 0000000..0309ae2
--- /dev/null
+++ b/vam/whittaker/_version.py
@@ -0,0 +1 @@
+__version__ = "2.0.2"
diff --git a/src/_whittaker.pyx b/vam/whittaker/_whittaker.pyx
similarity index 100%
rename from src/_whittaker.pyx
rename to vam/whittaker/_whittaker.pyx