diff --git a/src/usr.sbin/ntpd/ntp.c b/src/usr.sbin/ntpd/ntp.c
index 41d8f788..26bd5669 100644
--- a/src/usr.sbin/ntpd/ntp.c
+++ b/src/usr.sbin/ntpd/ntp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.98 2007/01/15 08:19:11 otto Exp $ */
+/*	$OpenBSD: ntp.c,v 1.99 2007/08/04 02:58:02 ckuethe Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -253,9 +253,12 @@ ntp_main(int pipe_prnt[2], struct ntpd_conf *nconf)
 
 		if (last_sensor_scan == 0 ||
 		    last_sensor_scan + SENSOR_SCAN_INTERVAL < getmonotime()) {
-			sensor_scan();
+			sensors_cnt = sensor_scan();
 			last_sensor_scan = getmonotime();
 		}
+		if (!TAILQ_EMPTY(&conf->ntp_conf_sensors) && sensors_cnt == 0 &&
+		    nextaction > last_sensor_scan + SENSOR_SCAN_INTERVAL)
+			nextaction = last_sensor_scan + SENSOR_SCAN_INTERVAL;
 		sensors_cnt = 0;
 		TAILQ_FOREACH(s, &conf->ntp_sensors, entry) {
 			if (conf->settime && s->offsets[0].offset)
diff --git a/src/usr.sbin/ntpd/ntpd.h b/src/usr.sbin/ntpd/ntpd.h
index 6f016cdc..daf17772 100644
--- a/src/usr.sbin/ntpd/ntpd.h
+++ b/src/usr.sbin/ntpd/ntpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.84 2007/04/30 01:33:33 deraadt Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.85 2007/08/04 02:58:02 ckuethe Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -308,7 +308,7 @@ struct s_fixedpt	d_to_sfp(double);
 
 /* sensors.c */
 void			sensor_init(void);
-void			sensor_scan(void);
+int			sensor_scan(void);
 void			sensor_query(struct ntp_sensor *);
 int			sensor_hotplugfd(void);
 void			sensor_hotplugevent(int);
diff --git a/src/usr.sbin/ntpd/sensors.c b/src/usr.sbin/ntpd/sensors.c
index 3df6cbdb..dde110f8 100644
--- a/src/usr.sbin/ntpd/sensors.c
+++ b/src/usr.sbin/ntpd/sensors.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sensors.c,v 1.32 2007/01/23 17:44:38 claudio Exp $ */
+/*	$OpenBSD: sensors.c,v 1.33 2007/08/04 02:58:02 ckuethe Exp $ */
 
 /*
  * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
@@ -45,16 +45,21 @@ sensor_init(void)
 	TAILQ_INIT(&conf->ntp_sensors);
 }
 
-void
+int
 sensor_scan(void)
 {
-	int		i;
+	int		i, n;
 	char		d[MAXDEVNAMLEN];
 	struct sensor	s;
 
+	n = 0;
 	for (i = 0; i < MAXSENSORDEVICES; i++)
-		if (sensor_probe(i, d, &s))
+		if (sensor_probe(i, d, &s)) {
 			sensor_add(i, d);
+			n++;
+		}
+
+	return n;
 }
 
 int