diff --git a/setup.py b/setup.py
index e6c67e6..0b7cbf0 100644
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,7 @@ test_requires = ['rasterio', 'dask', 'xarray', 'cartopy>=0.20.0', 'pillow', 'mat
 if sys.platform.startswith("win"):
     extra_compile_args = []
 else:
-    extra_compile_args = ["-O3", "-Wno-unused-function"]
+    extra_compile_args = ["-O2", "-Wno-unused-function"]
 
 extensions = [
     Extension("pyresample.ewa._ll2cr", sources=["pyresample/ewa/_ll2cr.pyx"],
@@ -82,7 +82,7 @@ if __name__ == "__main__":
     README = open('README.md', 'r').read()
     setup(name='pyresample',
           url='https://github.com/pytroll/pyresample',
-          version=versioneer.get_version(),
+          version='$PKGVER',
           cmdclass=cmdclass,
           description='Geospatial image resampling in Python',
           long_description=README,
@@ -90,13 +90,12 @@ if __name__ == "__main__":
           author='Thomas Lavergne',
           author_email='t.lavergne@met.no',
           package_dir={'pyresample': 'pyresample'},
-          packages=find_packages(),
-          package_data={'pyresample.test': ['test_files/*']},
+          packages=find_packages(exclude=['pyresample.test*']),
           python_requires='>=3.8',
           setup_requires=setup_requires,
           install_requires=requirements,
           extras_require=extras_require,
-          ext_modules=cythonize(extensions),
+          ext_modules=cythonize(extensions, language_level = "3"),
           entry_points=entry_points,
           zip_safe=False,
           classifiers=[