new file mode 100644
--- /dev/null
+++ b/ssl_curve.t
@@ -0,0 +1,124 @@
+#!/usr/bin/perl
+
+# (C) Sergey Kandaurov
+# (C) Nginx, Inc.
+
+# Tests for http ssl module, $ssl_curve variable.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+eval { require IO::Socket::SSL; };
+plan(skip_all => 'IO::Socket::SSL not installed') if $@;
+eval { IO::Socket::SSL::SSL_VERIFY_NONE(); };
+plan(skip_all => 'IO::Socket::SSL too old') if $@;
+
+my $t = Test::Nginx->new()->has(qw/http http_ssl rewrite/)
+	->has_daemon('openssl');
+
+$t->{_configure_args} =~ /OpenSSL (\d+)/;
+plan(skip_all => 'OpenSSL too old') unless defined $1 and $1 >= 3;
+
+$t->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    ssl_certificate_key localhost.key;
+    ssl_certificate localhost.crt;
+
+    ssl_ecdh_curve prime256v1;
+
+    server {
+        listen       127.0.0.1:8443 ssl;
+        server_name  localhost;
+
+        return 200 "$ssl_curve $ssl_curves";
+    }
+}
+
+EOF
+
+$t->write_file('openssl.conf', <<EOF);
+[ req ]
+default_bits = 2048
+encrypt_key = no
+distinguished_name = req_distinguished_name
+[ req_distinguished_name ]
+EOF
+
+my $d = $t->testdir();
+
+foreach my $name ('localhost') {
+	system('openssl req -x509 -new '
+		. "-config $d/openssl.conf -subj /CN=$name/ "
+		. "-out $d/$name.crt -keyout $d/$name.key "
+		. ">>$d/openssl.out 2>&1") == 0
+		or die "Can't create certificate for $name: $!\n";
+}
+
+$t->try_run('no $ssl_curve')->plan(1);
+
+###############################################################################
+
+like(get('/curve'), qr/^prime256v1 /m, 'ssl curve');
+
+###############################################################################
+
+sub get {
+	my ($uri, $port, $ctx) = @_;
+	my $s = get_ssl_socket($port) or return;
+	my $r = http_get($uri, socket => $s);
+	$s->close();
+	return $r;
+}
+
+sub get_ssl_socket {
+	my ($port, $ctx) = @_;
+	my $s;
+
+	eval {
+		local $SIG{ALRM} = sub { die "timeout\n" };
+		local $SIG{PIPE} = sub { die "sigpipe\n" };
+		alarm(8);
+		$s = IO::Socket::SSL->new(
+			Proto => 'tcp',
+			PeerAddr => '127.0.0.1',
+			PeerPort => port(8443),
+			SSL_verify_mode => IO::Socket::SSL::SSL_VERIFY_NONE(),
+			SSL_error_trap => sub { die $_[1] },
+		);
+		alarm(0);
+	};
+	alarm(0);
+
+	if ($@) {
+		log_in("died: $@");
+		return undef;
+	}
+
+	return $s;
+}
+
+###############################################################################