diff --git a/_includes/sections/file-encryption.html b/_includes/sections/file-encryption.html
index 868a1cce..e39d747c 100644
--- a/_includes/sections/file-encryption.html
+++ b/_includes/sections/file-encryption.html
@@ -53,7 +53,7 @@
 <h3>Worth Mentioning</h3>
 
 <ul>
-  <li><a href="https://cryptomator.org/">Cryptomator</a> - Free client-side AES encryption for your cloud files. Open-source software: No backdoors, no registration.</li>
+  <li><a href="https://cryptomator.org/">Cryptomator</a> - Free client-side AES encryption for your cloud files. Open source software: No backdoors, no registration. <span class="badge badge-warning" data-toggle="tooltip" title="Cryptomator's mobile apps are not open-source."><a href="https://github.com/cryptomator/cryptomator-android/issues/1#issuecomment-257979375"><i class="fas fa-exclamation-triangle"></i></a></span></li></li>
   <li><a href="https://gitlab.com/cryptsetup/cryptsetup/">Linux Unified Key Setup (LUKS)</a> - A full disk encryption system for Linux using dm-crypt as the disk encryption backend. Included by default in Ubuntu. Available for Windows and Linux.</li>
   <li><a href="https://hat.sh/">Hat.sh</a> - A cross-platform, serverless JavaScript web application that provides secure file encryption using the AES-256-GCM algorithm in your browser. It can also be downloaded and run offline.</a></li>
   <li><a href="https://www.keka.io/">Keka</a> - A macOS-only, open-source file archiver with the ability to encrypt files.</li>