diff --git a/Dockerfile b/Dockerfile
index 7322729..7754eb3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,7 +2,7 @@
 ## "base" stage
 ##################################################
 
-FROM docker.io/python:3.12-slim-bookworm AS base
+FROM docker.io/python:3.12-slim-bookworm@sha256:a64ac5be6928c6a94f00b16e09cdf3ba3edd44452d10ffa4516a58004873573e AS base
 
 ARG USER=oasch
 ARG UID=49374