diff --git a/mpi_dummy/__init__.py b/mpi_dummy/__init__.py
index 0684974d7f8a1d37381764d150a8e7653a1df2f7..b89f68233e9579a8851398a7973724a70d62c85c 100644
--- a/mpi_dummy/__init__.py
+++ b/mpi_dummy/__init__.py
@@ -16,8 +16,9 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+from __future__ import absolute_import
 from .version import __version__
 
-from comm import *
-from datatypes import *
-from op import *
+from .comm import *
+from .datatypes import *
+from .op import *
diff --git a/mpi_dummy/comm.py b/mpi_dummy/comm.py
index 15ae8173915094ba2fdd1a9bb69efd538ee460a0..6ef1f5fb87244a0933e722afa578890047ba77a9 100644
--- a/mpi_dummy/comm.py
+++ b/mpi_dummy/comm.py
@@ -1,11 +1,13 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
+from builtins import object
 import inspect
 
 import copy
 import numpy as np
 
-from op import SUM
+from .op import SUM
 
 __all__ = ['Comm', 'Intracomm', 'COMM_WORLD', 'COMM_SELF']
 
diff --git a/mpi_dummy/datatypes.py b/mpi_dummy/datatypes.py
index 303302c260dbcbf0cfccd2176ddd1f138b160571..5f5f1b4a81b47b563f461f9a88179a81464c9f08 100644
--- a/mpi_dummy/datatypes.py
+++ b/mpi_dummy/datatypes.py
@@ -1,11 +1,13 @@
 # -*- coding: utf-8 -*-
+from builtins import str
+from builtins import object
 
 __all__ = ['BYTE', 'SHORT', 'UNSIGNED_SHORT', 'UNSIGNED_INT', 'INT', 'LONG',
            'UNSIGNED_LONG', 'LONG_LONG', 'UNSIGNED_LONG_LONG', 'FLOAT',
            'DOUBLE', 'LONG_DOUBLE', 'COMPLEX', 'DOUBLE_COMPLEX']
 
 
-class _datatype():
+class _datatype(object):
     def __init__(self, name):
         self.name = str(name)
 
diff --git a/mpi_dummy/op.py b/mpi_dummy/op.py
index b6eabd0a8c86c83f0a1142839f8c3d5d22b49409..9ae81f6c41b14266a5c3da144c0cb61140e613d5 100644
--- a/mpi_dummy/op.py
+++ b/mpi_dummy/op.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from builtins import object
 
 
 class Op(object):
@@ -13,4 +14,4 @@ PROD = Op()
 LAND = Op()
 LOR = Op()
 BAND = Op()
-BOR = Op()
\ No newline at end of file
+BOR = Op()