Add needed package to README
diff --git a/README b/README
index 04e294d..f813105 100644
--- a/README
+++ b/README
@@ -10,7 +10,7 @@
 
 1. Install Ubuntu 14.04 or Debian 7.5 64-bit.
 2. Install the packages necessary for the build:
-> sudo apt-get install cscope ctags libz-dev libexpat-dev libc6-dev-i386 gcc g++ git bison flex gcc-multilib g++-multilib libxml-simple-perl libxml-sax-perl
+> sudo apt-get install cscope ctags libz-dev libexpat-dev libc6-dev-i386 gcc g++ git bison flex gcc-multilib g++-multilib libxml-simple-perl libxml-sax-perl libxml2-dev
 3. Continue with the clone, environment setup, and build as noted above.
 
 Building on *64-bit* Fedora systems