diff --git a/Dockerfile b/Dockerfile
index f9b0fb0..6c8af85 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,10 @@
-#use 32-bit ubuntu 12.04 required by valgrind. 64-bit has some known issues
-from shawn/ubuntu-precise-i386
+from ubuntu:16.04
 MAINTAINER David Liu <email4dliu@gmail.com>
 
 LABEL Description="Do your C/C++ development in Docker container. Based on Ubuntu, and added build-essential and valgrind so you can use g++/gcc/gdb/valgrind."
 
+#update package files to ensure newest versions
+run apt-get update
 
 #adds gcc valgrind
 run apt-get install -y build-essential valgrind 
diff --git a/build.sh b/build.sh
index b309b8b..c10f9dd 100755
--- a/build.sh
+++ b/build.sh
@@ -1,3 +1,3 @@
 # To build the image from Dockerfile, use this command:
-#docker build -t="dliu/ubuntu-gcc-valgrind" .
+docker build -t="dliu/ubuntu-gcc-valgrind" .