diff --git a/src/openalea/mtg/interface/mtg.py b/src/openalea/mtg/interface/mtg.py
index ebc27ce..7932bb7 100644
--- a/src/openalea/mtg/interface/mtg.py
+++ b/src/openalea/mtg/interface/mtg.py
@@ -18,7 +18,7 @@
 This module provides multiscale tree concepts to form MTG interface.
 """
 
-class MultiscaleTreeConcept(object):
+class MultiscaleTreeConcept():
     """
     Multiscale Tree Graph definition.
     """
diff --git a/src/openalea/mtg/mtg.py b/src/openalea/mtg/mtg.py
index b330c64..320a16d 100644
--- a/src/openalea/mtg/mtg.py
+++ b/src/openalea/mtg/mtg.py
@@ -2753,7 +2753,7 @@ def new_f(self, *args, **kwds):
     new_f.__doc__ = mtg_f.__doc__
     return new_f
 
-class _ProxyNode(object):
+class _ProxyNode():
     def __init__(self, g, vid):
         self.__dict__['_g'] = g
         self.__dict__['_vid'] = vid
diff --git a/src/openalea/mtg/plantframe/dresser.py b/src/openalea/mtg/plantframe/dresser.py
index 5267218..5bef0e4 100644
--- a/src/openalea/mtg/plantframe/dresser.py
+++ b/src/openalea/mtg/plantframe/dresser.py
@@ -43,7 +43,7 @@
 import os
 from openalea.plantgl.scenegraph import AmapSymbol
 
-class DressingData(object):
+class DressingData():
     """ Data and default geometric parameters.
 
     The dressing data are the default data that are used to define 
@@ -205,7 +205,7 @@ def dressing_data(file):
 
 ###############################################################
 ## Define the parser which is just a dict from keyword to a function 
-class Reader(object):
+class Reader():
     def __init__(self, dresser):
         self.dresser = dresser
         
diff --git a/src/openalea/mtg/plantframe/frame.py b/src/openalea/mtg/plantframe/frame.py
index 893780e..ff41431 100644
--- a/src/openalea/mtg/plantframe/frame.py
+++ b/src/openalea/mtg/plantframe/frame.py
@@ -34,7 +34,7 @@
 
 
 
-class Frame(object):
+class Frame():
     """ Frame representing geometric variables of each topologic elements.
     
     A frame is used to have a common representation of the geometric information 
@@ -137,7 +137,7 @@ def get_top_radius(self):
     top_radius = property(get_top_radius, set_top_radius, 'top_radius of the Frame')
 
 
-class AxialFrames(object):
+class AxialFrames():
     ''' Solve continuity constraints on an axis, i.e. a set of frames.
 
     '''
@@ -145,7 +145,7 @@ class AxialFrames(object):
 
 
 
-class PlantFrame(object):
+class PlantFrame():
     ''' Engine to compute the geometry of a plant based on 
     its topological description and parameters.
     '''
diff --git a/src/openalea/mtg/plantframe/plantframe.py b/src/openalea/mtg/plantframe/plantframe.py
index 66d221b..c35c8cd 100644
--- a/src/openalea/mtg/plantframe/plantframe.py
+++ b/src/openalea/mtg/plantframe/plantframe.py
@@ -56,7 +56,7 @@
 error = True
 epsilon = 1e-5
 
-class PlantFrame(object):
+class PlantFrame():
     ''' Engine to compute the geometry of a plant based on
     its topological description and parameters.
     '''
diff --git a/src/openalea/mtg/rewriting.py b/src/openalea/mtg/rewriting.py
index 0dd566f..c41dda1 100644
--- a/src/openalea/mtg/rewriting.py
+++ b/src/openalea/mtg/rewriting.py
@@ -20,7 +20,7 @@
 
 #### Module declaration #######
 
-class Module(object):
+class Module():
     def __init__(self, name, scale, **parameters):
         self.name = name
         self.scale = scale
@@ -299,7 +299,7 @@ def interpretation(f):
 
 eForward, eBackward = 1,0
 
-class MTGLsystem(object):
+class MTGLsystem():
     rules = dict()
 
     def __init__(self):
diff --git a/src/openalea/mtg/traversal.py b/src/openalea/mtg/traversal.py
index 4b9f2f0..c0d7d2e 100644
--- a/src/openalea/mtg/traversal.py
+++ b/src/openalea/mtg/traversal.py
@@ -271,7 +271,7 @@ def traverse_tree(tree, vtx_id, visitor):
   yield visitor.post_order(vtx_id)
 
 
-class Visitor(object):
+class Visitor():
   ''' Used during a tree traversal. '''
 
   def pre_order(self, vtx_id): 
diff --git a/src/openalea/mtg/tree.py b/src/openalea/mtg/tree.py
index dd2d66a..faad5c0 100644
--- a/src/openalea/mtg/tree.py
+++ b/src/openalea/mtg/tree.py
@@ -43,7 +43,7 @@ class InvalidVertex (GraphError, KeyError) :
     exception raised when a wrong vertex id is provided
     """
 
-class Tree(object):
+class Tree():
     '''
     Implementation of a rooted :class:`Tree`, 
     with methods to add and remove vertex.
diff --git a/src/openalea/mtg/version.py b/src/openalea/mtg/version.py
index 15d5f2e..5429bda 100644
--- a/src/openalea/mtg/version.py
+++ b/src/openalea/mtg/version.py
@@ -7,7 +7,7 @@
 minor = 2
 """(int) Version minor component."""
 
-post = 0
+post = 1
 """(int) Version post or bugfix component."""
 
 __version__ = ".".join([str(s) for s in (major, minor, post)])