diff --git a/test/end-to-end/automate/Dockerfile b/test/end-to-end/automate/Dockerfile
index f76760f5a5..7e337ab9b2 100644
--- a/test/end-to-end/automate/Dockerfile
+++ b/test/end-to-end/automate/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu
+FROM ubuntu@sha256:9101220a875cee98b016668342c489ff0674f247f6ca20dfc91b91c0f28581ae
 
 # We need curl
 RUN apt-get update && apt-get -y install curl
diff --git a/test/end-to-end/multi-supervisor/Dockerfile b/test/end-to-end/multi-supervisor/Dockerfile
index beaa26df57..420e0c7bf0 100644
--- a/test/end-to-end/multi-supervisor/Dockerfile
+++ b/test/end-to-end/multi-supervisor/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu
+FROM ubuntu@sha256:9101220a875cee98b016668342c489ff0674f247f6ca20dfc91b91c0f28581ae
 
 # Channel from which to install Habitat-related packages
 ARG CHANNEL=stable