diff --git a/README.rst b/README.rst
index d863328c..42758b8a 100644
--- a/README.rst
+++ b/README.rst
@@ -10,8 +10,8 @@ MessagePack for Python
    :target: https://msgpack-python.readthedocs.io/en/latest/?badge=latest
    :alt: Documentation Status
 
-Upgrading from msgpack-0.4
---------------------------
+IMPORTANT: Upgrading from msgpack-0.4
+--------------------------------------
 
 TL;DR: When upgrading from msgpack-0.4 or earlier, don't do `pip install -U msgpack-python`.
 Do `pip uninstall msgpack-python; pip install msgpack` instead.
diff --git a/dummy/README b/dummy/README
deleted file mode 100644
index bf1eeb63..00000000
--- a/dummy/README
+++ /dev/null
@@ -1,2 +0,0 @@
-This is dummy transition package for msgpak.
-Install msgpack instead of msgpack-python.
diff --git a/dummy/setup.py b/dummy/setup.py
deleted file mode 100644
index 0f1e6e72..00000000
--- a/dummy/setup.py
+++ /dev/null
@@ -1,31 +0,0 @@
-from setuptools import setup, Extension
-
-long_desc = """\
-msgpack-python is renamed to just msgpack.
-
-Install msgpack by ``pip install msgpack``.
-"""
-
-
-setup(name='msgpack-python',
-      author='INADA Naoki',
-      author_email='songofacandy@gmail.com',
-      version="0.5.0",
-      description="Transition package for msgpack",
-      long_description=long_desc,
-      install_requires=["msgpack>=0.5"],
-      url='http://msgpack.org/',
-      license='Apache 2.0',
-      classifiers=[
-          'Programming Language :: Python :: 2',
-          'Programming Language :: Python :: 2.7',
-          'Programming Language :: Python :: 3',
-          'Programming Language :: Python :: 3.5',
-          'Programming Language :: Python :: 3.6',
-          'Programming Language :: Python :: 3.7',
-          'Programming Language :: Python :: Implementation :: CPython',
-          'Programming Language :: Python :: Implementation :: PyPy',
-          'Intended Audience :: Developers',
-          'License :: OSI Approved :: Apache Software License',
-      ],
-)
diff --git a/setup.py b/setup.py
index 419482bd..61085874 100755
--- a/setup.py
+++ b/setup.py
@@ -9,6 +9,9 @@
 
 from distutils.command.build_ext import build_ext
 
+# for building transitional package.
+TRANSITIONAL = False
+
 class NoCython(Exception):
     pass
 
@@ -102,7 +105,13 @@ def __init__(self, *args, **kwargs):
     long_desc = f.read()
 del f
 
-setup(name='msgpack',
+name = 'msgpack'
+
+if TRANSITIONAL:
+    name = 'msgpack-python'
+    long_desc = "This package is deprecated.  Install msgpack instead."
+
+setup(name=name,
       author='INADA Naoki',
       author_email='songofacandy@gmail.com',
       version=version_str,