diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8cb522f..e552e96 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Changed
+
++ Based Docker image on Python 3.9
+
 ## [4.1.0] - 2020-11-11
 
 ### Changed
diff --git a/Dockerfile b/Dockerfile
index a9f969a..0779cf7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-FROM python:3.8-slim-buster
+FROM python:3.9-slim-buster
 
 ARG USER_ID=1000
 ARG GROUP_ID=1000