diff --git a/app/Dockerfile b/app/Dockerfile
index 4a43f5f..4a23a97 100644
--- a/app/Dockerfile
+++ b/app/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.9
+FROM alpine:3.23@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11
 ADD app /
 ADD index.html.tmpl /
 EXPOSE 80
diff --git a/db/Dockerfile b/db/Dockerfile
index 3d8f660..f28a2be 100644
--- a/db/Dockerfile
+++ b/db/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.9
+FROM alpine:3.23@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11
 ADD db /
 EXPOSE 80
 ENTRYPOINT [ "/db" ]
diff --git a/lint-image/Dockerfile b/lint-image/Dockerfile
index 953cc71..f6fe9cd 100644
--- a/lint-image/Dockerfile
+++ b/lint-image/Dockerfile
@@ -1,5 +1,5 @@
 # Build jsonnet
-FROM alpine:3.11 AS jsonnet-builder
+FROM alpine:3.23@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11 AS jsonnet-builder
 RUN apk add --no-cache git make g++
 RUN git clone https://github.com/google/jsonnet && \
     git  -C jsonnet checkout v0.14.0 && \
@@ -15,7 +15,7 @@ RUN git clone https://github.com/jsonnet-bundler/jsonnet-bundler /jsonnet-bundle
     git checkout v0.2.0 && \
     make install
 
-FROM alpine:3.11
+FROM alpine:3.23@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11
 RUN apk add --no-cache git make libgcc libstdc++ zip
 COPY --from=jsonnet-builder /usr/bin/jsonnetfmt /usr/bin
 COPY --from=jsonnet-builder /usr/bin/jsonnet /usr/bin
diff --git a/loadgen/Dockerfile b/loadgen/Dockerfile
index f6bcfdc..311af1c 100644
--- a/loadgen/Dockerfile
+++ b/loadgen/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.9
+FROM alpine:3.23@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11
 ADD loadgen /
 ADD stories.json /
 EXPOSE 80