diff --git a/Dockerfile b/Dockerfile
index 87bb058..ced8aa6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:xenial
+FROM ubuntu:zesty
 MAINTAINER Andrey Arapov <andrey.arapov@nixaid.com>
 
 # To avoid problems with Dialog and curses wizards
diff --git a/docker-compose.yml b/docker-compose.yml
index dec62c4..34e808a 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -28,4 +28,5 @@ services:
     # more on CAP_SYS_ADMIN https://lwn.net/Articles/486306/
     cap_add:
       - SYS_ADMIN
+      - IPC_LOCK # lock memory to prevent sensitive values from being swapped to disk.
     shm_size: 4G