diff --git a/README.md b/README.md
index 16f81dc..527102e 100644
--- a/README.md
+++ b/README.md
@@ -3,3 +3,5 @@
 Recent releases of ghc and the supporting build tools (stack and cabal) are available only for the newest darwin systems.
 
 Here there are build instructions for older darwin systems and binary releases needed to bootstrap these older systems.
+
+At present, 64bit Intel (x86_64) builds are available, back to darwin 10 (SnowLeopard).