diff --git a/concourse/images/Dockerfile.bionic.erb b/concourse/images/Dockerfile.bionic.erb
index 1a25403f7a4..c21b9aee9a0 100644
--- a/concourse/images/Dockerfile.bionic.erb
+++ b/concourse/images/Dockerfile.bionic.erb
@@ -1,4 +1,4 @@
-FROM ubuntu:bionic
+FROM ubuntu:18.04
 
 <%= File.read "debian-prelude.step" %>