diff --git a/sample-btcd.conf b/sample-btcd.conf
index 6eab03f9..7cf38e6c 100644
--- a/sample-btcd.conf
+++ b/sample-btcd.conf
@@ -160,7 +160,10 @@
 ; ------------------------------------------------------------------------------
 
 ; Debug logging level.
-; Valid options are {trace, debug, info, warn, error, critical}
+; Valid levels are {trace, debug, info, warn, error, critical}
+; You may also specify <subsystem>=<level>,<subsystem2>=<level>,... to set
+; log level for individual subsystems.  Use btcd --debuglevel=show to list
+; available subsystems.
 ; debuglevel=info
 
 ; The port used to listen for HTTP profile requests.  The profile server will