diff --git a/README.md b/README.md
index e1e76ef8..bb1e336c 100644
--- a/README.md
+++ b/README.md
@@ -73,6 +73,7 @@ If you're not inclined to make PRs you can tweet me at ```@ripienaar```
   * https://www.ssllabs.com/ssltest/ - Very deep analysis of the configuration of any SSL web server
   * https://qualys.com/forms/freescan/owasp/ - Find web app vulnerabilities, audit for OWASP Risks
   * [alienvault.com ThreatFinder](https://www.alienvault.com/open-threat-exchange/threatfinder) - Uncovers compromised systems in your network
+  * https://duosecurity.com - Two-factor authentication (2FA) for website or app. Free 10 users, all authentication methods, unlimited, integrations, hardware tokens.
 
 ## Management Systems