diff --git a/README.md b/README.md
index 04b34cbc07c98e73740b13200ed83fe067af99d2..602df33cecfc8ec37fd791e3257221e66f120cb3 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,7 @@ However, you can also create an issue for it.
 
 * Copyright (C) 2018 Research Group Biomedical Physics, Max Planck Institute
   for Dynamics and Self-Organization Göttingen.
-* Copyright (C) 2020-2021 Indiscale GmbH <info@indiscale.com>
+* Copyright (C) 2020-2022 Indiscale GmbH <info@indiscale.com>
 
 All files in this repository are licensed under a [GNU Affero General Public
 License](LICENCE.md) (version 3 or later).
diff --git a/RELEASE_GUIDELINES.md b/RELEASE_GUIDELINES.md
index b4e38d643756798f0ba8b07d6eceec529cbb3054..00d0362e6630267c135e2566b993a91fccf1fd91 100644
--- a/RELEASE_GUIDELINES.md
+++ b/RELEASE_GUIDELINES.md
@@ -42,4 +42,6 @@ guidelines of the CaosDB Project
 
 12. After the merge of main to dev, start a new development version by
     setting `ISRELEASED` to `False` and by increasing at least the `MICRO`
-    version in [setup.py](./setup.py) and preparing CHANGELOG.md.
+    version in [setup.py](./setup.py).
+    Also update CHANGELOG.md (new "Unreleased" section).
+    Also update `src/doc/conf.py`.
diff --git a/setup.py b/setup.py
index af9e680981ba7a802e22fcde706cb6b73dc7f6dc..9f392889c314bb54b0557f53793a034f6d5161b5 100755
--- a/setup.py
+++ b/setup.py
@@ -45,15 +45,15 @@ from setuptools import find_packages, setup
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ########################################################################
 
-ISRELEASED = True
+ISRELEASED = False
 MAJOR = 0
-MINOR = 8
+MINOR = 9
 MICRO = 0
 # Do not tag as pre-release until this commit
 # https://github.com/pypa/packaging/pull/515
 # has made it into a release. Probably we should wait for pypa/packaging>=21.4
 # https://github.com/pypa/packaging/releases
-PRE = "" # "dev"  # e.g. rc0, alpha.1, 0.beta-23
+PRE = "dev" # "dev"  # e.g. rc0, alpha.1, 0.beta-23
 
 if PRE:
     VERSION = "{}.{}.{}-{}".format(MAJOR, MINOR, MICRO, PRE)
diff --git a/src/doc/conf.py b/src/doc/conf.py
index 77531343d49a9bfa9b1d30d7681f040509d0c336..9e65bff1eba5d114a77d3ed9405e883df6ad7470 100644
--- a/src/doc/conf.py
+++ b/src/doc/conf.py
@@ -29,10 +29,10 @@ copyright = '2022, IndiScale GmbH'
 author = 'Daniel Hornung'
 
 # The short X.Y version
-version = '0.8.0'
+version = '0.9.0'
 # The full version, including alpha/beta/rc tags
 # release = '0.5.2-rc2'
-release = '0.8.0'
+release = '0.9.0-dev'
 
 
 # -- General configuration ---------------------------------------------------