Adding step for packages to readme.
diff --git a/README.md b/README.md
index b585dd9..6cef6ad 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,10 @@
     cd $JOSHUA
     mvn clean package
 
+Install required (Ubuntu) packages:
+
+    sudo apt-get install cmake libbz2-dev liblzma-dev libboost-all-dev ant gcc g++
+
 You also need to download and compile [KenLM](http://kheafield.com/code/kenlm/) and [Thrax](https://github.com/joshua-decoder/thrax):
 
     bash ./download-deps.sh