diff --git a/Dockerfile b/Dockerfile
index 70de9f3..0681643 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM thegeeklab/alpine:latest
+FROM thegeeklab/alpine:latest@sha256:58bffcff0cb1124cd0489a0168c56e097637919422edd111b1e96220ed631c28
 
 LABEL maintainer="Robert Kaussow <mail@thegeeklab.de>"
 LABEL org.opencontainers.image.authors="Robert Kaussow <mail@thegeeklab.de>"