diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index 6fea3d4..d320f87 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -14,7 +14,7 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.6, 3.7, 3.8, 3.9.0-rc.1]
 
     steps:
     - uses: actions/checkout@v1
diff --git a/setup.py b/setup.py
index 0d51428..e7ea789 100644
--- a/setup.py
+++ b/setup.py
@@ -46,6 +46,7 @@ def get_version_and_cmdclass(package_path):
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
     ],
     packages=find_packages(),
     keywords="plant sensor bluetooth low-energy ble",
diff --git a/tox.ini b/tox.ini
index 4cd8880..8e14855 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,7 +7,7 @@ python =
     3.6: py36, flake8, pylint, noimport
     3.7: py37
     3.8: py38, pre-commit
-    3.9: py39
+    3.9.0-rc.1: py39
 
 [testenv]
 # only run unit tests as they do not need additional hardware