diff --git a/misc.c b/misc.c
index 07d4179e479..65c9222aa8b 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.106 2016/10/23 22:04:05 dtucker Exp $ */
+/* $OpenBSD: misc.c,v 1.107 2016/11/30 00:28:31 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -1251,3 +1251,21 @@ bind_permitted(int port, uid_t uid)
 		return 0;
 	return 1;
 }
+
+/* returns 1 if process is already daemonized, 0 otherwise */
+int
+daemonized(void)
+{
+	int fd;
+
+	if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
+		close(fd);
+		return 0;	/* have controlling terminal */
+	}
+	if (getppid() != 1)
+		return 0;	/* parent is not init */
+	if (getsid(0) != getpid())
+		return 0;	/* not session leader */
+	debug3("already daemonized");
+	return 1;
+}
diff --git a/misc.h b/misc.h
index 3578e8ef539..c242f9011f5 100644
--- a/misc.h
+++ b/misc.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.h,v 1.60 2016/10/23 22:04:05 dtucker Exp $ */
+/* $OpenBSD: misc.h,v 1.61 2016/11/30 00:28:31 dtucker Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -31,6 +31,7 @@ struct Forward {
 
 int forward_equals(const struct Forward *, const struct Forward *);
 int bind_permitted(int, uid_t);
+int daemonized(void);
 
 /* Common server and client forwarding options. */
 struct ForwardOptions {
diff --git a/sshd.c b/sshd.c
index ce4a493ef88..fafcd3400b8 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.477 2016/11/29 03:54:50 dtucker Exp $ */
+/* $OpenBSD: sshd.c,v 1.478 2016/11/30 00:28:31 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1343,7 +1343,7 @@ main(int ac, char **av)
 	struct ssh *ssh = NULL;
 	extern char *optarg;
 	extern int optind;
-	int r, opt, i, j, on = 1;
+	int r, opt, i, j, on = 1, already_daemon;
 	int sock_in = -1, sock_out = -1, newsock = -1;
 	const char *remote_ip;
 	int remote_port;
@@ -1802,11 +1802,12 @@ main(int ac, char **av)
 	log_init(__progname, options.log_level, options.log_facility, log_stderr);
 
 	/*
-	 * If not in debugging mode, and not started from inetd, disconnect
-	 * from the controlling terminal, and fork.  The original process
-	 * exits.
+	 * If not in debugging mode, not started from inetd and not already
+	 * daemonized (eg re-exec via SIGHUP), disconnect from the controlling
+	 * terminal, and fork.  The original process exits.
 	 */
-	if (!(debug_flag || inetd_flag || no_daemon_flag)) {
+	already_daemon = daemonized();
+	if (!(debug_flag || inetd_flag || no_daemon_flag || already_daemon)) {
 
 		if (daemon(0, 0) < 0)
 			fatal("daemon() failed: %.200s", strerror(errno));
@@ -1840,7 +1841,7 @@ main(int ac, char **av)
 		 * Write out the pid file after the sigterm handler
 		 * is setup and the listen sockets are bound
 		 */
-		if (options.pid_file != NULL && !debug_flag) {
+		if (options.pid_file != NULL && !debug_flag && !already_daemon) {
 			FILE *f = fopen(options.pid_file, "w");
 
 			if (f == NULL) {