diff --git a/README.md b/README.md
index 28bc989e61a..9d976b1c289 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 ## The Servo Parallel Browser Project
 
-I currently build on OS X and Linux.
+Servo currently builds on Mac OS X and Linux. Since the Rust language is currently in flux, you
+will need the bleeding-edge (Git master) version of the Rust compiler.
 
 ### Prerequisites