diff --git a/man/bmon.8 b/man/bmon.8
index c94f1ba..07e0148 100644
--- a/man/bmon.8
+++ b/man/bmon.8
@@ -44,7 +44,7 @@ text mode. See OUTPUT MODULES for more details.
 .PP
 \fB \-U\fR, \fB\-\-use\-si\fR
 .RS 4
-Use SI unit system instead of 1KB = 1'024 bytes.
+Use SI unit system (1KB = 1'000 bytes) instead of 1KB = 1'024 bytes.
 .RE
 .PP
 \fB \-f\fR, \fB\-\-configfile=\fRFILE