diff --git a/Security-Tokens.md b/Security-Tokens.md
index 8cbdd34..111be34 100644
--- a/Security-Tokens.md
+++ b/Security-Tokens.md
@@ -35,6 +35,8 @@ Besides Fidesmo, YubiKey, we don't know of other NFC-enabled security tokens tha
   * [J3A040 or J3A080 from smartcardsource.com](http://www.smartcardsource.com) (NOT TESTED)
   * [J3A040 or J3A080 from motechno.com](http://www.motechno.com) (NOT TESTED)
 
+## Are external USB Smartcard Reader supported?
+Not officially. However, you can turn on "Allow untested USB Devices", under experimental settings and try your reader. It must have a CCID interface and you should insert the OpenPGP card before plugging in the reader. We found that Nexus 5X reboots, but Nexus 6P works. Readers on [this page](https://pcsclite.alioth.debian.org/ccid/supported.html) will work with higher probability but we cannot provide any recommendations, we still recommend one of the supported security tokens from the table above. Some discussions about this is in [#1912](https://github.com/open-keychain/open-keychain/issues/1912)
 
 ## No OpenPGP support
 These security tokens do not support OpenPGP: