diff --git a/lib/httparty/cookie_hash.rb b/lib/httparty/cookie_hash.rb
index 119964f..674696e 100644
--- a/lib/httparty/cookie_hash.rb
+++ b/lib/httparty/cookie_hash.rb
@@ -1,6 +1,6 @@
 class HTTParty::CookieHash < Hash #:nodoc:
 
-  CLIENT_COOKIES = %w{path expires domain path secure HTTPOnly}
+  CLIENT_COOKIES = %w{path expires domain path secure httponly}
 
   def add_cookies(value)
     case value