diff --git a/Dockerfile b/Dockerfile
index 4b33a4e..18c1c5c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.22.0
+FROM alpine:3.22.0@sha256:8a1f59ffb675680d47db6337b49d22281a139e9d709335b492be023728e11715
 
 RUN apk add --no-cache build-base bash docker-cli git \
     && git clone -b add-ipv6-support https://github.com/Alphix/mdns-repeater.git \