diff --git a/docker/Dockerfile.linux.amd64 b/docker/Dockerfile.linux.amd64
index 7cca021..989899b 100644
--- a/docker/Dockerfile.linux.amd64
+++ b/docker/Dockerfile.linux.amd64
@@ -1,4 +1,4 @@
-FROM alpine:3.19@sha256:c5b1261d6d3e43071626931fc004f70149baeba2c8ec672bd4f27761f8e1ad6b
+FROM alpine:3.21@sha256:a8560b36e8b8210634f77d9f7f9efd7ffa463e380b75e2e74aff4511df3ef88c
 RUN apk add --no-cache ca-certificates mailcap && \
 	echo "@testing http://nl.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories
 
diff --git a/docker/Dockerfile.linux.multiarch b/docker/Dockerfile.linux.multiarch
index 5f4e901..d58190f 100644
--- a/docker/Dockerfile.linux.multiarch
+++ b/docker/Dockerfile.linux.multiarch
@@ -1,4 +1,4 @@
-FROM alpine:3.19@sha256:c5b1261d6d3e43071626931fc004f70149baeba2c8ec672bd4f27761f8e1ad6b as alpine
+FROM alpine:3.21@sha256:a8560b36e8b8210634f77d9f7f9efd7ffa463e380b75e2e74aff4511df3ef88c as alpine
 RUN apk add --no-cache ca-certificates mailcap
 
 FROM scratch