diff --git a/README.md b/README.md
index 8b88e5b..d7cb3c1 100644
--- a/README.md
+++ b/README.md
@@ -440,6 +440,7 @@ every 20 minutes, look at something 20 feet (~6 meters) away for at least 20 sec
 
 * [AdwCleaner](https://toolslib.net/downloads/viewdownload/1-adwcleaner/) - Removal tool for adware, PUP/LPI, toolbars and hijackers.
 * [Bitdefender](https://www.bitdefender.com/) - Comprehensive malware protection suite.
+* [capyknock](https://plinioseniore.github.io/capyknock/) - Single Packet Authorization in fwknop style [![Open-Source Software][oss]](https://github.com/plinioseniore/capyknock)
 * [Certificate Ripper](https://github.com/Hakky54/certificate-ripper) - A CLI tool to extract server certificates from a URL. [![Open-Source Software][oss]](https://github.com/Hakky54/certificate-ripper)
 * [cppcryptfs](https://github.com/bailey27/cppcryptfs) - cppcryptfs is an implementation of the gocryptfs encrypted overlay filesystem in C++ for Windows  
 * [Cryptomator](https://cryptomator.org/) - Client-side encryption for cloud files. [![Open-Source Software][oss]](https://github.com/cryptomator/cryptomator)