diff --git a/Dockerfile b/Dockerfile
index 2abca56..6cdc164 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-from golang:1.21.4-alpine3.18 as build
+from golang:1.21.5-alpine3.19 as build
 
 workdir /src
 copy go.mod go.sum .
@@ -9,7 +9,7 @@ run go test ./...
 run go build -o /go/bin/init -trimpath .
 
 # ------------------------------------------------------------------------
-from alpine:3.18.4 as initrd
+from alpine:3.19.0 as initrd
 
 run apk add --no-cache xz
 
@@ -27,6 +27,6 @@ run chroot /layer /init hello
 run find |cpio -H newc -o >/initrd
 
 # ------------------------------------------------------------------------
-from alpine:3.18.4
+from alpine:3.19.0
 copy --from=initrd /initrd /
 entrypoint ["base64","/initrd"]