diff --git a/README.md b/README.md
index da2a193..8fb5962 100644
--- a/README.md
+++ b/README.md
@@ -297,6 +297,7 @@ Reference links
 * https://www.linode.com/docs/websites/nginx/configure-nginx-for-optimized-performance
 * https://haydenjames.io/nginx-tuning-tips-tls-ssl-https-ttfb-latency/
 * https://medium.freecodecamp.org/a8afdbfde64d
+* https://medium.freecodecamp.org/secure-your-web-application-with-these-http-headers-fd66e0367628
 
 Static analyzers
 ----------------