diff --git a/Dockerfile b/Dockerfile
index 39c2fa8ed..dae792b94 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM openjdk:8-jdk-alpine
+FROM openjdk:8-jdk-alpine@sha256:94792824df2df33402f201713f932b58cb9de94a0cd524164a0f2283343547b3
 COPY bin/coursier coursier
 RUN apk add --no-cache git curl \
     && git config --global user.email "you@example.com" \
diff --git a/Dockerfile.template b/Dockerfile.template
index c8a1cf3e3..e05d249dd 100644
--- a/Dockerfile.template
+++ b/Dockerfile.template
@@ -1,4 +1,4 @@
-FROM openjdk:8-jdk-alpine
+FROM openjdk:8-jdk-alpine@sha256:94792824df2df33402f201713f932b58cb9de94a0cd524164a0f2283343547b3
 COPY bin/coursier coursier
 RUN apk add --no-cache git curl \
     && git config --global user.email "you@example.com" \