diff --git a/Dockerfile b/Dockerfile
index a2e4319..4ad0c57 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:bullseye-slim
+FROM debian:bullseye-slim@sha256:fbaacd55d14bd0ae0c0441c2347217da77ad83c517054623357d1f9d07f79f5e
 
 LABEL maintainer="Robert Kaussow <mail@thegeeklab.de>"
 LABEL org.opencontainers.image.authors="Robert Kaussow <mail@thegeeklab.de>"