diff --git a/python/openEMS/_nf2ff.pyx b/python/openEMS/_nf2ff.pyx
index cd3de34..4f7ecdc 100644
--- a/python/openEMS/_nf2ff.pyx
+++ b/python/openEMS/_nf2ff.pyx
@@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-cimport _nf2ff
+cimport openEMS._nf2ff
 import numpy as np
 import os
 from CSXCAD.Utilities import CheckNyDir
diff --git a/python/openEMS/openEMS.pyx b/python/openEMS/openEMS.pyx
index d2596dd..dff801f 100644
--- a/python/openEMS/openEMS.pyx
+++ b/python/openEMS/openEMS.pyx
@@ -19,7 +19,7 @@
 import os, sys, shutil
 import numpy as np
 cimport openEMS
-from . import ports, nf2ff, automesh
+from openEMS import ports, nf2ff, automesh
 
 from CSXCAD.Utilities import GetMultiDirs
 
diff --git a/python/setup.py b/python/setup.py
index 3a2221b..0ac0ba0 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -40,8 +40,8 @@ setup(
   author_email = 'Thorsten.Liebig@gmx.de',
   maintainer = 'Thorsten Liebig',
   maintainer_email = 'Thorsten.Liebig@gmx.de',
-  url = 'http://openEMS.de',
+  url = 'https://openEMS.de',
   packages=["openEMS", ],
   package_data={'openEMS': ['*.pxd']},
-  ext_modules = cythonize(extensions)
+  ext_modules = cythonize(extensions, language_level = "3")
  )