diff --git a/usr.sbin/vipw/vipw.8 b/usr.sbin/vipw/vipw.8
index 5e8be4bc64bc..69f884539646 100644
--- a/usr.sbin/vipw/vipw.8
+++ b/usr.sbin/vipw/vipw.8
@@ -28,7 +28,7 @@
 .\"     @(#)vipw.8	8.1 (Berkeley) 6/6/93
 .\" $FreeBSD$
 .\"
-.Dd February 10, 2012
+.Dd February 14, 2012
 .Dt VIPW 8
 .Os
 .Sh NAME
@@ -110,3 +110,13 @@ The
 .Nm
 utility appeared in
 .Bx 4.0 .
+.Sh BUGS
+The mechanism for checking for password file modifications requires that
+the modification time of the password file changes.
+This means that in a default configuration where file system timestamps
+are not calculated with sub-second precision,
+.Ev EDITOR
+has to run for at least one second.
+Non-interactive editor scripts should invoke
+.Xr sleep 1
+or equivalent to ensure this happens.