diff --git a/compat/Makefile.am b/compat/Makefile.am
index d49786c..fd7242a 100644
--- a/compat/Makefile.am
+++ b/compat/Makefile.am
@@ -48,6 +48,10 @@ libcompat_la_SOURCES += adjfreq_solaris.c
 endif
 endif
 
+if HOST_OPENBSD
+libcompat_la_SOURCES += adjfreq_openbsd.c
+endif
+
 if !HAVE_ASPRINTF
 libcompat_la_SOURCES += bsd-asprintf.c
 endif
diff --git a/compat/adjfreq_freebsd.c b/compat/adjfreq_freebsd.c
index f631b17..8011dad 100644
--- a/compat/adjfreq_freebsd.c
+++ b/compat/adjfreq_freebsd.c
@@ -57,3 +57,20 @@ adjfreq(const int64_t *freq, int64_t *oldfreq)
 
 	return 0;
 }
+
+/*
+ * The RTC is only updated if the clock is not marked as unsynced.
+ */
+
+void
+update_time_sync_status(int synced)
+{
+	struct timex txc = { 0 };
+
+	txc.modes = MOD_STATUS;
+	if (!synced)
+		txc.status = STA_UNSYNC;
+	if (ntp_adjtime(&txc) == -1)
+		log_warn("ntp_adjtime (3) failed");
+	return;
+}
diff --git a/compat/adjfreq_linux.c b/compat/adjfreq_linux.c
index 5c5e6e5..217b23a 100644
--- a/compat/adjfreq_linux.c
+++ b/compat/adjfreq_linux.c
@@ -57,3 +57,20 @@ adjfreq(const int64_t *freq, int64_t *oldfreq)
 
 	return 0;
 }
+
+/*
+ * The RTC is only updated if the clock is not marked as unsynced.
+ */
+
+void
+update_time_sync_status(int synced)
+{
+	struct timex txc = { 0 };
+
+	txc.modes = MOD_STATUS;
+	if (!synced)
+		txc.status = STA_UNSYNC;
+	if (adjtimex(&txc) == -1)
+		log_warn("ntp_adjtime (3) failed");
+	return;
+}
diff --git a/compat/adjfreq_netbsd.c b/compat/adjfreq_netbsd.c
index 332ff2c..f533966 100644
--- a/compat/adjfreq_netbsd.c
+++ b/compat/adjfreq_netbsd.c
@@ -58,3 +58,20 @@ adjfreq(const int64_t *freq, int64_t *oldfreq)
 
 	return 0;
 }
+
+/*
+ * The RTC is only updated if the clock is not marked as unsynced.
+ */
+
+void
+update_time_sync_status(int synced)
+{
+	struct timex txc = { 0 };
+
+	txc.modes = MOD_STATUS;
+	if (!synced)
+		txc.status = STA_UNSYNC;
+	if (ntp_adjtime(&txc) == -1)
+		log_warn("ntp_adjtime (3) failed");
+	return;
+}
diff --git a/compat/adjfreq_openbsd.c b/compat/adjfreq_openbsd.c
new file mode 100644
index 0000000..4d9fa6b
--- /dev/null
+++ b/compat/adjfreq_openbsd.c
@@ -0,0 +1,10 @@
+/*
+ * This file is in the public domain.
+ *
+ * adjfreq is native on OpenBSD, but we need to stub in update_time_sync_status
+ */
+
+void
+update_time_sync_status(int synced)
+{
+}
diff --git a/compat/adjfreq_osx.c b/compat/adjfreq_osx.c
index f8f0be4..c8a875b 100644
--- a/compat/adjfreq_osx.c
+++ b/compat/adjfreq_osx.c
@@ -17,3 +17,8 @@ adjfreq(const int64_t *freq, int64_t *oldfreq)
 	errno = ENOSYS;
 	return -1;
 }
+
+void
+update_time_sync_status(int synced)
+{
+}
diff --git a/compat/adjfreq_solaris.c b/compat/adjfreq_solaris.c
index f631b17..8011dad 100644
--- a/compat/adjfreq_solaris.c
+++ b/compat/adjfreq_solaris.c
@@ -57,3 +57,20 @@ adjfreq(const int64_t *freq, int64_t *oldfreq)
 
 	return 0;
 }
+
+/*
+ * The RTC is only updated if the clock is not marked as unsynced.
+ */
+
+void
+update_time_sync_status(int synced)
+{
+	struct timex txc = { 0 };
+
+	txc.modes = MOD_STATUS;
+	if (!synced)
+		txc.status = STA_UNSYNC;
+	if (ntp_adjtime(&txc) == -1)
+		log_warn("ntp_adjtime (3) failed");
+	return;
+}
diff --git a/configure.ac b/configure.ac
index 4bbccae..8c142a2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -50,6 +50,7 @@ case $host_os in
 		HOST_OS=netbsd
 		;;
 	*openbsd*)
+		HOST_OS=openbsd
 		AC_DEFINE([HAVE_ATTRIBUTE__BOUNDED__], [1], [OpenBSD has __bounded__])
 		AC_DEFINE([HAVE_ATTRIBUTE__DEAD], [1], [OpenBSD has __dead])
 		;;
@@ -65,6 +66,7 @@ AM_CONDITIONAL([HOST_DARWIN],  [test x$HOST_OS = xdarwin])
 AM_CONDITIONAL([HOST_FREEBSD], [test x$HOST_OS = xfreebsd])
 AM_CONDITIONAL([HOST_LINUX],   [test x$HOST_OS = xlinux])
 AM_CONDITIONAL([HOST_NETBSD],  [test x$HOST_OS = xnetbsd])
+AM_CONDITIONAL([HOST_OPENBSD],  [test x$HOST_OS = xopenbsd])
 AM_CONDITIONAL([HOST_SOLARIS], [test x$HOST_OS = xsolaris])
 
 AC_CHECK_FUNC([dl_iterate_phdr],,
diff --git a/ntpd.conf b/ntpd.conf
index 2446fc7..d403a71 100644
--- a/ntpd.conf
+++ b/ntpd.conf
@@ -18,4 +18,4 @@ servers pool.ntp.org
 #sensor *
 
 # get the time constraint from a well-known HTTPS site
-#constraints from "https://www.google.com/search?q=openntpd"
+constraints from "https://www.google.com/search?q=openntpd"
diff --git a/patches/0012-add-a-method-for-updating-the-realtime-clock-on-sync.patch b/patches/0012-add-a-method-for-updating-the-realtime-clock-on-sync.patch
new file mode 100644
index 0000000..2b0a27b
--- /dev/null
+++ b/patches/0012-add-a-method-for-updating-the-realtime-clock-on-sync.patch
@@ -0,0 +1,33 @@
+From 6d482d31602ce3fc0b17f155d2306a27bad09bec Mon Sep 17 00:00:00 2001
+From: Brent Cook <busterb@gmail.com>
+Date: Mon, 4 May 2015 04:27:29 -0500
+Subject: [PATCH 12/12] add a method for updating the realtime clock on sync
+
+from Christian Weisgerber
+---
+ src/usr.sbin/ntpd/ntpd.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/src/usr.sbin/ntpd/ntpd.c b/src/usr.sbin/ntpd/ntpd.c
+index 44caa80..fb9a8df 100644
+--- a/src/usr.sbin/ntpd/ntpd.c
++++ b/src/usr.sbin/ntpd/ntpd.c
+@@ -53,6 +53,7 @@ const char     *ctl_lookup_option(char *, const char **);
+ void		show_status_msg(struct imsg *);
+ void		show_peer_msg(struct imsg *, int);
+ void		show_sensor_msg(struct imsg *, int);
++void		update_time_sync_status(int);
+ 
+ volatile sig_atomic_t	 quit = 0;
+ volatile sig_atomic_t	 reconfig = 0;
+@@ -423,6 +424,7 @@ ntpd_adjtime(double d)
+ 	else if (!firstadj && olddelta.tv_sec == 0 && olddelta.tv_usec == 0)
+ 		synced = 1;
+ 	firstadj = 0;
++	update_time_sync_status(synced);
+ 	return (synced);
+ }
+ 
+-- 
+2.2.1.209.g41e5f3a
+