diff --git a/Dockerfile b/Dockerfile
index 4e4f0b47abd07791889296cb479eb02bf2977cbf..74654b14cf1a3589a951fc2cf3c34132d1fdfb2a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM amd64/node:8.12.0-alpine
+FROM amd64/node:8.12.0-alpine@sha256:81abb8de1e5e8b6e55bca143b3c2ec1e2d167cb27fd2cd3191a0d222f7c5e710
 
 LABEL maintainer="Rhys Arkins <rhys@arkins.net>"
 LABEL name="renovate"