diff --git a/distarray/__init__.py b/distarray/__init__.py
index 1f78c73d..50942d14 100644
--- a/distarray/__init__.py
+++ b/distarray/__init__.py
@@ -4,5 +4,5 @@
 #  Distributed under the terms of the BSD License.  See COPYING.rst.
 # ---------------------------------------------------------------------------
 
-__version__ = "0.3.0"
+__version__ = "0.4.0-dev"
 DISTARRAY_BASE_NAME = '__distarray__'
diff --git a/docs/source/conf.py b/docs/source/conf.py
index ec79abf7..394800cd 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -69,9 +69,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = '0.3'
+version = '0.4'
 # The full version, including alpha/beta/rc tags.
-release = '0.3.0'
+release = '0.4.0-dev'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/setup.py b/setup.py
index b103ef74..fadfa501 100644
--- a/setup.py
+++ b/setup.py
@@ -14,7 +14,7 @@
 
 metadata = {
     'name': 'distarray',
-    'version': '0.3.0',
+    'version': '0.4.0-dev',
     'description': 'Distributed Memory Arrays for Python',
     'keywords': 'parallel mpi distributed array',
     'license': 'New BSD',