diff --git a/README.md b/README.md
index 4c8d61f..f445ef8 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,8 @@ IntaroCRM REST API client
 ===============
 
 PHP Client for [IntaroCRM REST API](http://docs.intarocrm.ru/rest-api/).
+
+Requirements:
+
+* PHP version 5.3 and above
+* PHP-extension CURL