diff --git a/README.md b/README.md
index 610f1e2..9902516 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,9 @@
 # inc-incident-handling-fx
 InCommon Incident Handling Framework document in asciidoc format
 ## Prerequisites
-1. asciidoctor
+1. ruby >=2.1.0
+2. asciidoctor
+3. 
 ## Rendering
 ### HTML
 asciidoctor main.adoc -o docs/index.html