diff --git a/readme.md b/readme.md
index 36a810ec73..fbd092cd04 100644
--- a/readme.md
+++ b/readme.md
@@ -21,4 +21,6 @@ change, I'm not even sure if the performance characteristics of Rx make Observab
 binding throughout a framework. *I'm writing this only to see if the idea of exploring these ideas 
 appeals to anyone else.*
 
-[Take a look at the introduction document here.](Docs/intro.md)
\ No newline at end of file
+[Take a look at the introduction document here.](Docs/intro.md)
+
+**NOTE**: This uses proposed C#6 features so you'll have to install a Roslyn preview. [If you're using VS2013, try here.]( https://connect.microsoft.com/VisualStudio/Downloads/DownloadDetails.aspx?DownloadID=52793)