diff --git a/.bumpversion.cfg b/.bumpversion.cfg
index 608b931..678abf1 100644
--- a/.bumpversion.cfg
+++ b/.bumpversion.cfg
@@ -1,17 +1,17 @@
 [bumpversion]
-current_version = 2.3.2
+current_version = 2.3.3-dev0
 commit = True
 tag = True
 commit_args = --no-verify
 parse = (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)(\-(?P<release>[a-z]+)(?P<build>\d+))?
-serialize =
+serialize = 
 	{major}.{minor}.{patch}-{release}{build}
 	{major}.{minor}.{patch}
 
 [bumpversion:part:release]
 optional_value = _
 first_value = dev
-values =
+values = 
 	dev
 	_
 
diff --git a/README.md b/README.md
index 494ec1c..40b93be 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# **B**io**F**ormats **I**nput/**O**utput utility (bfio 2.3.2)
+# **B**io**F**ormats **I**nput/**O**utput utility (bfio 2.3.3-dev0)
 
 [![Documentation Status](https://readthedocs.org/projects/bfio/badge/?version=latest)](https://bfio.readthedocs.io/en/latest/?badge=latest)
 [![PyPI](https://img.shields.io/pypi/v/bfio)](https://pypi.org/project/filepattern/)
@@ -48,15 +48,15 @@ be installed using pip:
 
 ## Docker
 
-### polusai/bfio:2.3.2
+### polusai/bfio:2.3.3-dev0
 
 Ubuntu based container with bfio and all dependencies (including Java).
 
-### polusai/bfio:2.3.2-imagej
+### polusai/bfio:2.3.3-dev0-imagej
 
 Same as above, except comes with ImageJ and PyImageJ.
 
-### polusai/bfio:2.3.2-tensorflow
+### polusai/bfio:2.3.3-dev0-tensorflow
 
 Tensorflow container with bfio installed.
 
diff --git a/VERSION b/VERSION
index f90b1af..d11b36a 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.2
+2.3.3-dev0
diff --git a/requirements/requirements-base.txt b/requirements/requirements-base.txt
index 2efeb9a..4e54cd6 100644
--- a/requirements/requirements-base.txt
+++ b/requirements/requirements-base.txt
@@ -1 +1 @@
-bfio[all]==2.3.1
+bfio[all]==2.3.3-dev0