--- a/h2.t
+++ b/h2.t
@@ -32,7 +32,7 @@ plan(skip_all => 'IO::Socket::SSL too ol
 
 my $t = Test::Nginx->new()->has(qw/http http_ssl http_v2 proxy cache/)
 	->has(qw/limit_conn rewrite realip shmem/)
-	->has_daemon('openssl')->plan(193);
+	->has_daemon('openssl')->plan(194);
 
 $t->write_file_expand('nginx.conf', <<'EOF');
 
@@ -1712,6 +1712,16 @@ is($frame->{headers}->{':status'}, 400, 
 ($frame) = grep { $_->{type} eq "HEADERS" } @$frames;
 is($frame->{headers}->{':status'}, 400, 'empty authority');
 
+# unknown frame type
+
+$sess = new_session();
+h2_unknown($sess, 'payload');
+h2_ping($sess, 'SEE-THIS');
+$frames = h2_read($sess, all => [{ type => 'PING' }]);
+
+($frame) = grep { $_->{type} eq "PING" } @$frames;
+is($frame->{value}, 'SEE-THIS', 'unknown frame type');
+
 # GOAWAY - force closing a connection by server
 
 $sid = new_stream($sess, { path => 't1.html' });
@@ -1762,6 +1772,13 @@ sub h2_settings {
 	raw_write($sess->{socket}, $buf);
 }
 
+sub h2_unknown {
+	my ($sess, $payload) = @_;
+
+	my $buf = pack_length(length($payload)) . pack("Cx5a*", 0xa, $payload);
+	raw_write($sess->{socket}, $buf);
+}
+
 sub h2_continue {
 	my ($ctx, $stream, $uri) = @_;