diff --git a/README.md b/README.md
index 664c658c..0724fe9f 100644
--- a/README.md
+++ b/README.md
@@ -3,4 +3,8 @@
 <H1>Coming Soon!</H1>
 <H1>Do not use it, unless you know what you are doing !</H1>
 
-[![Build Status](https://travis-ci.org/luc-github/ESP3D.svg?branch=3.0)](https://travis-ci.org/luc-github/ESP3D) 
+[![Build Status](https://travis-ci.org/luc-github/ESP3D.svg?branch=3.0)](https://travis-ci.org/luc-github/ESP3D)
+
+The esp8266 core need to be 2.6 at least.   
+The esp82 core need to be 1.0.4 at least.  
+So currently only git version of both cores should compile.