diff --git a/README.md b/README.md
index 8d8e59d..bbffcb8 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,8 @@ a minimal Linux kernel module written in rust.
 ## Requirements
 
  - A recent build of Rust (latest nightly)
+ - Xargo (install with `cargo install xargo`)
+ - Rust source code (install with `rustup component add rust-src`)
 
 This code uses [feature flags](http://blog.rust-lang.org/2014/10/30/Stability.html#the-plan), so
 you'll need to use a [nightly version of Rust](http://doc.rust-lang.org/book/nightly-rust.html)