diff --git a/Setup.md b/Setup.md
index 6c7b167..ea52fa8 100644
--- a/Setup.md
+++ b/Setup.md
@@ -31,6 +31,8 @@ A common set of options is:
 -Dfile.encoding=UTF8 -Xmx1536M -Xss1M -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256m
 ```
 
+**Note**: You can share the `project/boot` directory between all sbt projects on a machine by setting the `sbt.boot.directory` system property to the directory to use.  For example, `-Dsbt.boot.directory=/home/user/.sbt/boot/`.
+
 ## Unix
 Put the jar in your `~/bin` directory, put the line:
 ```text