diff --git a/regress/Nsd.pm b/regress/Nsd.pm
index 7c71194..a5f117d 100644
--- a/regress/Nsd.pm
+++ b/regress/Nsd.pm
@@ -34,7 +34,6 @@ sub new {
 	$args{ktraceexec} = $ENV{KTRACE} if $ENV{KTRACE};
 	$args{ktracefile} ||= "nsd.ktrace";
 	$args{logfile} ||= "nsd.log";
-	$args{serial} ||= time();
 	$args{up} ||= "nsd started";
 
 	my $self = Proc::new($class, %args);
@@ -68,6 +67,16 @@ sub new {
 	print $fh "	name: regress.\n";
 	print $fh "	zonefile: nsd.zone\n";
 
+	return $self->zone();
+}
+
+sub zone {
+	my $self = shift;
+	my %args = @_;
+	$args{serial} ||= time();
+	$self->{record_list} = $args{record_list} if $args{record_list};
+
+	my $test = basename($self->{testfile} || "");
 	open(my $fz, '>', "nsd.zone") or die ref($self),
 	    " zone file 'nsd.zone' create failed: $!";
 	print $fz "; test $test\n";
@@ -84,6 +93,10 @@ sub new {
 		print $fz "$r\n";
 	}
 
+	kill('HUP', $self->{pid}) or die
+	    ref($self), " kill HUP child '$self->{pid}' failed: $!"
+	    if $args{sighup};
+
 	return $self;
 }
 
diff --git a/regress/Pfctl.pm b/regress/Pfctl.pm
index c66580a..257ac78 100644
--- a/regress/Pfctl.pm
+++ b/regress/Pfctl.pm
@@ -54,6 +54,11 @@ sub child {
 }
 
 sub func {
+	my $self = shift;
+	$self->show();
+}
+
+sub show {
 	my $self = shift;
 	my @sudo = $ENV{SUDO} ? $ENV{SUDO} : ();
 
diff --git a/regress/Pfresolved.pm b/regress/Pfresolved.pm
index 2204f78..0b14f72 100644
--- a/regress/Pfresolved.pm
+++ b/regress/Pfresolved.pm
@@ -77,6 +77,7 @@ sub child {
 	my @cmd = (@sudo, @ktrace, $self->{execfile}, "-dvvv",
 	    "-f", $self->{conffile});
 	push @cmd, "-r", $resolver if $resolver;
+	push @cmd, "-m", $self->{min_ttl} if $self->{min_ttl};
 	if ($self->{tls}) {
 		my $ca = $self->{ca} || "ca.crt";
 		push @cmd, "-C", $ca if $self->{tls};
diff --git a/regress/args-ttl.pl b/regress/args-ttl.pl
new file mode 100644
index 0000000..e47498e
--- /dev/null
+++ b/regress/args-ttl.pl
@@ -0,0 +1,96 @@
+# Create zone file with A and AAAA records in zone regress.
+# Start nsd with zone file with TTL 2 seconds and listening on 127.0.0.1.
+# Write hosts of regress zone into pfresolved config.
+# Start pfresolved with nsd as resolver.
+# Wait until pfresolved creates table regress-pfresolved.
+# Write new zone file with all adresses changed.
+# Wait until TTL has expired and pfresolved has renewed adresses.
+# Read IP addresses from pf table with pfctl.
+# Check that pfresolved added IPv4 and IPv6 addresses.
+# Check that pf table contains new IPv4 and IPv6 addresses with short TTL.
+# Check that pf table contains old IPv4 and IPv6 addresses with default TTL.
+# Check that pfresolved removed IPv4 and IPv6 addresses with short TTL.
+
+use strict;
+use warnings;
+use Socket;
+
+our %args = (
+    nsd => {
+	listen => { domain => AF_INET, addr => "127.0.0.1" },
+	record_list => [
+	    "foo		A	192.0.2.1",
+	    "bar		AAAA	2001:DB8::1",
+	    "foobar	2	A	192.0.2.2",
+	    "foobar	2	AAAA	2001:DB8::2",
+	],
+	loggrep => {
+	    qr/listen on ip-address 127.0.0.1\@\d+ \(udp\)/ => 1,
+	    qr/listen on ip-address [0-9A-Fa-f:]+\@\d+ / => 0,
+	},
+    },
+    pfresolved => {
+	address_list => [ map { "$_.regress." } qw(foo bar foobar) ],
+	min_ttl => 1,
+	loggrep => {
+	    qr/-m 1/ => 1,
+	    qr{added: 192.0.2.1/32,} => 1,
+	    qr{added: 2001:db8::1/128,} => 1,
+	    qr{added: 192.0.2.2/32,} => 1,
+	    qr{added: 2001:db8::2/128,} => 1,
+	    qr/starting new resolve request for .* in 3 seconds/ => 2,
+	    qr{removed: 192.0.2.1/32} => 0,
+	    qr{removed: 2001:db8::1/128} => 0,
+	    qr{removed: 192.0.2.2/32$} => 1,
+	    qr{removed: 2001:db8::2/128$} => 1,
+	    qr{added: 192.0.2.10/32,} => 0,
+	    qr{added: 2001:db8::10/128,} => 0,
+	    qr{added: 192.0.2.20/32,} => 1,
+	    qr{added: 2001:db8::20/128,} => 1,
+	},
+    },
+    pfctl => {
+	updated => [4, 1],
+	func => sub {
+	    my $self = shift;
+	    my $nsd = $self->{nsd};
+	    my $pfresolved = $self->{pfresolved};
+
+	    $self->show();
+	    $nsd->zone(
+		record_list => [
+		    "foo		A	192.0.2.10",
+		    "bar		AAAA	2001:DB8::10",
+		    "foobar	 	A	192.0.2.20",
+		    "foobar	 	AAAA	2001:DB8::20",
+		],
+		sighup => 1,
+	    );
+
+	    # wait at most until TTL has expired
+	    my $timeout = 3;
+	    my ($updates, $deleted) = (2, 1);
+	    my $table =
+		qr/updated addresses for pf table .*, deleted: $deleted,/;
+	    my $tomsg = $timeout ? " after $timeout seconds" : "";
+	    my $upmsg = $updates ? " for $updates times" : "";
+	    $pfresolved->loggrep($table, $timeout, $updates)
+		or die ref($self), " no '$table' in $pfresolved->{logfile}",
+		    $tomsg, $upmsg;
+
+	    $self->show();
+	},
+	loggrep => {
+	    qr/^   192.0.2.1$/ => 2,
+	    qr/^   192.0.2.2$/ => 1,
+	    qr/^   192.0.2.10$/ => 0,  # foo not updated
+	    qr/^   192.0.2.20$/ => 1,  # foobar updated after ttl expired
+	    qr/^   2001:db8::1$/ => 2,
+	    qr/^   2001:db8::2$/ => 1,
+	    qr/^   2001:db8::10$/ => 0,  # foo not updated
+	    qr/^   2001:db8::20$/ => 1,  # foobar updated after ttl expired
+	},
+    },
+);
+
+1;
diff --git a/regress/pfresolved.pl b/regress/pfresolved.pl
index 7d3540a..78576ff 100644
--- a/regress/pfresolved.pl
+++ b/regress/pfresolved.pl
@@ -52,6 +52,7 @@ sub usage {
 );
 my $s = Pfctl->new(
     %{$args{pfctl}},
+    nsd			=> $n,
     pfresolved		=> $d,
 ) if $args{pfctl};