diff --git a/ci/compile.Dockerfile b/ci/compile.Dockerfile
index 45c9d1f..3194de6 100644
--- a/ci/compile.Dockerfile
+++ b/ci/compile.Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.22.0
+FROM alpine:3.22.0@sha256:8a1f59ffb675680d47db6337b49d22281a139e9d709335b492be023728e11715
 
 RUN apk add --no-cache \
     gcc=14.2.0-r6 \
diff --git a/ci/unit-test.Dockerfile b/ci/unit-test.Dockerfile
index 68db5ea..5a40fcc 100644
--- a/ci/unit-test.Dockerfile
+++ b/ci/unit-test.Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.22.0
+FROM alpine:3.22.0@sha256:8a1f59ffb675680d47db6337b49d22281a139e9d709335b492be023728e11715
 
 RUN apk add --no-cache \
     gcc=14.2.0-r6 \