diff --git a/README.md b/README.md
index 3476411..5e69917 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,15 @@
 # denonavr
-[![Version](https://img.shields.io/badge/version-v0.9.10-orange.svg)](https://github.com/scarface-4711/denonavr)
+[![Version](https://img.shields.io/badge/version-v0.10.0-orange.svg)](https://github.com/scarface-4711/denonavr)
 [![Build Status](https://travis-ci.com/scarface-4711/denonavr.svg?branch=master)](https://travis-ci.com/scarface-4711/denonavr)
 [![PyPi](https://img.shields.io/pypi/v/denonavr.svg)](https://pypi.org/project/denonavr)
 [![License](https://img.shields.io/github/license/scarface-4711/denonavr.svg)](LICENSE)
 
-Automation Library for Denon AVR receivers - current version 0.9.10
+Automation Library for Denon AVR receivers - current version 0.10.0
+
+## Important change
+
+This library switched to async in version 0.10.0.
+All sync methods are still available for a while in order not to break too many things. However using those methods is ineffecient, because they use the corresponding async methods by starting and stopping an own asyncio event loop for each command. Please switch to `async_` methods instead.
 
 ## Installation
 
diff --git a/README.rst b/README.rst
index f6f02da..e10c055 100644
--- a/README.rst
+++ b/README.rst
@@ -4,7 +4,15 @@ denonavr
 .. |Build Status| .. image:: https://travis-ci.com/scarface-4711/denonavr.svg?branch=master
     :target: https://travis-ci.com/scarface-4711/denonavr
 
-Automation Library for Denon AVR receivers - current version 0.9.10
+Automation Library for Denon AVR receivers - current version 0.10.0
+
+Important change
+----------------
+
+This library switched to async in version 0.10.0.
+All sync methods are still available for a while in order not to break too many things.
+However using those methods is ineffecient, because they use the corresponding async methods
+by starting and stopping an own asyncio event loop for each command. Please switch to `async_` methods instead.
 
 Installation
 ------------
diff --git a/denonavr/__init__.py b/denonavr/__init__.py
index 7954672..431d0ef 100644
--- a/denonavr/__init__.py
+++ b/denonavr/__init__.py
@@ -18,7 +18,7 @@
 logging.getLogger(__name__).addHandler(logging.NullHandler())
 
 __title__ = "denonavr"
-__version__ = "0.10.0.dev1"
+__version__ = "0.10.0"
 
 
 async def async_discover():
diff --git a/setup.py b/setup.py
index f0ef2b0..569019b 100644
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@
 from setuptools import find_packages, setup
 
 setup(name='denonavr',
-      version='0.10.0.dev1',
+      version='0.10.0',
       description='Automation Library for Denon AVR receivers',
       long_description='Automation Library for Denon AVR receivers',
       url='https://github.com/scarface-4711/denonavr',