bump ubuntu version
diff --git a/Dockerfile b/Dockerfile
index 5d945a9..b69b7fd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM       ubuntu:14.04.2
+FROM       ubuntu:14.04.3
 MAINTAINER Andy Bavier <acb@cs.princeton.edu>
 
 # XXX Workaround for docker bug: