diff --git a/Dockerfile b/Dockerfile
index 8407eda..28a9d16 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-ARG FROM_IMAGE=python:slim
+ARG FROM_IMAGE=python:3.10-slim-bullseye
 FROM $FROM_IMAGE
 LABEL maintainer "Praekelt.org <sre@praekelt.org>"