diff --git a/hash/Dockerfile b/hash/Dockerfile
index 4341558..4081a8a 100644
--- a/hash/Dockerfile
+++ b/hash/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.19.1
+FROM alpine:3.19.1@sha256:c5b1261d6d3e43071626931fc004f70149baeba2c8ec672bd4f27761f8e1ad6b
 
 # hadolint ignore=DL3018
 RUN apk --update --no-cache add apache2-utils argon2 coreutils openssl perl-archive-zip perl-utils rhash xxhash \