diff --git a/Dockerfile b/Dockerfile
index 279d17b..e1be341 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:latest
+FROM ubuntu:latest@sha256:67211c14fa74f070d27cc59d69a7fa9aeff8e28ea118ef3babc295a0428a6d21
 RUN apt-get update
 # RUN apt-get upgrade
 # RUN apt-get build-essential