diff --git a/Dockerfile b/Dockerfile
index 3960b080..0ef53a58 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@
 # To overwrite the build args use:
 #  docker build ... --build-arg UBUNTU_DATE=20171006
 ARG UBUNTU_FLAVOR=xenial
-ARG UBUNTU_DATE=20180417
+ARG UBUNTU_DATE=20180525
 
 #== Ubuntu xenial is 16.04, i.e. FROM ubuntu:16.04
 # Find latest images at https://hub.docker.com/r/library/ubuntu/