document that darwin is broken
diff --git a/README.md b/README.md
index 2ad52eb..e5c14e0 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,9 @@
 
 Pty is a Go package for using unix pseudo-terminals.
 
+(Note, the Darwin implementation doesn't work. If you
+are interested in fixing it, I'd appreciate a patch!)
+
 ## Install
 
     goinstall github.com/kr/pty