diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 90d2da8..6f507eb 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,7 +1,7 @@
-image: "docker:latest"
+image: "docker:latest@sha256:7d85d0eda291f1a7ab6df4a9d1802b5ad4cf9145a088bd11188c78dcb5c7392b"
 
 services:
-  - "docker:dind"
+  - "docker:dind@sha256:7d85d0eda291f1a7ab6df4a9d1802b5ad4cf9145a088bd11188c78dcb5c7392b"
 
 before_script:
   - "docker login -u \"$CI_REGISTRY_USER\" -p \"$CI_REGISTRY_PASSWORD\" $CI_REGISTRY"
diff --git a/Dockerfile b/Dockerfile
index 1eb00ce..677e9af 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.23
+FROM alpine:3.23@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11
 LABEL maintainer="Julien Cabillot <dockerimages@cabillot.eu>"
 
 # Ce projet tourne en root, mais je ne vois pas encore comment l'en empecher.