diff --git a/README.md b/README.md
index 0e50a8b..e5d1723 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ Unirest is a set of lightweight HTTP libraries available in [multiple languages]
 ## Requirements
 
 - [cURL](http://php.net/manual/en/book.curl.php)
+- PHP 5.4+
 
 ## Installation