diff --git a/plugins/inputs/syslog/README.md b/plugins/inputs/syslog/README.md
index 6d251c0e9..fb6d26fb3 100644
--- a/plugins/inputs/syslog/README.md
+++ b/plugins/inputs/syslog/README.md
@@ -7,7 +7,8 @@ socket, [UDP](https://tools.ietf.org/html/rfc5426),
 framing.
 
 Syslog messages should be formatted according to
-[RFC 5424](https://tools.ietf.org/html/rfc5424).
+[RFC 5424](https://tools.ietf.org/html/rfc5424) (syslog protocol) or
+[RFC 3164](https://tools.ietf.org/html/rfc3164) (BSD syslog protocol).
 
 ## Global configuration options <!-- @/docs/includes/plugin_config.md -->