diff --git a/README.md b/README.md
index fd8a0dd..f2d3017 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,12 @@ SSOwat
 
 A simple SSO for nginx, written in Lua
 
+Requirements
+------------
+
+Nginx "Openresty" flavored : http://openresty.org/
+
+
 Example Nginx conf
 ------------------