diff --git a/src/usr.sbin/ntpd/ntp.c b/src/usr.sbin/ntpd/ntp.c
index f3f50413..02c5b6bd 100644
--- a/src/usr.sbin/ntpd/ntp.c
+++ b/src/usr.sbin/ntpd/ntp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.161 2019/11/10 19:24:47 otto Exp $ */
+/*	$OpenBSD: ntp.c,v 1.162 2019/11/11 06:32:52 otto Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -300,7 +300,8 @@ ntp_main(struct ntpd_conf *nconf, struct passwd *pw, int argc, char **argv)
 		idx_clients = i;
 
 		if (!TAILQ_EMPTY(&conf->ntp_conf_sensors) &&
-		    (constraint_cnt == 0 || conf->constraint_median != 0)) {
+		    (conf->trusted_sensors || constraint_cnt == 0 ||
+		    conf->constraint_median != 0)) {
 			if (last_sensor_scan == 0 ||
 			    last_sensor_scan + SENSOR_SCAN_INTERVAL <= getmonotime()) {
 				sensors_cnt = sensor_scan();
diff --git a/src/usr.sbin/ntpd/ntpd.c b/src/usr.sbin/ntpd/ntpd.c
index f60569ee..d54d35c8 100644
--- a/src/usr.sbin/ntpd/ntpd.c
+++ b/src/usr.sbin/ntpd/ntpd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.c,v 1.127 2019/11/11 01:04:55 deraadt Exp $ */
+/*	$OpenBSD: ntpd.c,v 1.128 2019/11/11 06:32:52 otto Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -114,8 +114,8 @@ auto_preconditions(const struct ntpd_conf *cnf)
 	if (sysctl(mib, 2, &securelevel, &sz, NULL, 0) == -1)
 		err(1, "sysctl");
 	constraints = !TAILQ_EMPTY(&cnf->constraints);
-	return !cnf->settime && (constraints || cnf->trusted_peers) &&
-	    securelevel == 0;
+	return !cnf->settime && (constraints || cnf->trusted_peers ||
+	    conf->trusted_sensors) && securelevel == 0;
 }
 
 #define POLL_MAX		8
diff --git a/src/usr.sbin/ntpd/ntpd.h b/src/usr.sbin/ntpd/ntpd.h
index 3f1ffbf7..04940e76 100644
--- a/src/usr.sbin/ntpd/ntpd.h
+++ b/src/usr.sbin/ntpd/ntpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.147 2019/11/10 19:24:47 otto Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.148 2019/11/11 06:32:52 otto Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -189,6 +189,7 @@ struct ntp_sensor {
 	u_int8_t			 stratum;
 	u_int8_t			 weight;
 	u_int8_t			 shift;
+	u_int8_t			 trusted;
 };
 
 struct constraint {
@@ -213,6 +214,7 @@ struct ntp_conf_sensor {
 	int					 correction;
 	u_int8_t				 stratum;
 	u_int8_t				 weight;
+	u_int8_t				 trusted;
 };
 
 struct ntp_freq {
@@ -242,6 +244,7 @@ struct ntpd_conf {
 	u_int8_t					noaction;
 	u_int8_t					filters;
 	u_int8_t					trusted_peers;
+	u_int8_t					trusted_sensors;
 	time_t						constraint_last;
 	time_t						constraint_median;
 	u_int						constraint_errors;
diff --git a/src/usr.sbin/ntpd/parse.y b/src/usr.sbin/ntpd/parse.y
index 51f1ddb0..8d7ab09d 100644
--- a/src/usr.sbin/ntpd/parse.y
+++ b/src/usr.sbin/ntpd/parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.75 2019/11/10 19:24:47 otto Exp $ */
+/*	$OpenBSD: parse.y,v 1.76 2019/11/11 06:32:52 otto Exp $ */
 
 /*
  * Copyright (c) 2002, 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -183,6 +183,8 @@ main		: LISTEN ON address listen_opts	{
 				p = new_peer();
 				p->weight = $3.weight;
 				p->trusted = $3.trusted;
+				conf->trusted_peers = conf->trusted_peers ||
+				    $3.trusted;
 				p->query_addr4 = query_addr4;
 				p->query_addr6 = query_addr6;
 				p->addr = h;
@@ -223,6 +225,8 @@ main		: LISTEN ON address listen_opts	{
 
 			p->weight = $3.weight;
 			p->trusted = $3.trusted;
+			conf->trusted_peers = conf->trusted_peers ||
+			    $3.trusted;
 			p->query_addr4 = query_addr4;
 			p->query_addr6 = query_addr6;
 			p->addr_head.a = p->addr;
@@ -319,6 +323,9 @@ main		: LISTEN ON address listen_opts	{
 			s->correction = $3.correction;
 			s->refstr = $3.refstr;
 			s->stratum = $3.stratum;
+			s->trusted = $3.trusted;
+			conf->trusted_sensors = conf->trusted_sensors ||
+			    $3.trusted;
 			free($2);
 			TAILQ_INSERT_TAIL(&conf->ntp_conf_sensors, s, entry);
 		}
@@ -428,6 +435,7 @@ sensor_opt	: correction
 		| refid
 		| stratum
 		| weight
+		| trusted
 		;
 
 correction	: CORRECTION NUMBER {
@@ -481,7 +489,6 @@ rtable		: RTABLE NUMBER {
 
 trusted		: TRUSTED	{
 			opts.trusted = 1;
-			conf->trusted_peers = 1;
 		}
 
 %%
diff --git a/src/usr.sbin/ntpd/sensors.c b/src/usr.sbin/ntpd/sensors.c
index 4ca9a554..ff0eec09 100644
--- a/src/usr.sbin/ntpd/sensors.c
+++ b/src/usr.sbin/ntpd/sensors.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sensors.c,v 1.53 2019/11/10 07:32:58 otto Exp $ */
+/*	$OpenBSD: sensors.c,v 1.54 2019/11/11 06:32:52 otto Exp $ */
 
 /*
  * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
@@ -134,6 +134,7 @@ sensor_add(int sensordev, char *dxname)
 	s->weight = cs->weight;
 	s->correction = cs->correction;
 	s->stratum = cs->stratum - 1;
+	s->trusted = cs->trusted;
 	if ((s->device = strdup(dxname)) == NULL)
 		fatal("sensor_add strdup");
 	s->sensordevid = sensordev;
@@ -195,7 +196,7 @@ sensor_query(struct ntp_sensor *s)
 
 	s->last = sensor.tv.tv_sec;
 	
-	if (!TAILQ_EMPTY(&conf->constraints)) {
+	if (!s->trusted && !TAILQ_EMPTY(&conf->constraints)) {
 		if (conf->constraint_median == 0) {
 			return;
 		}