diff --git a/t/disconnect.t b/t/disconnect.t
new file mode 100644
index 0000000..98d309b
--- /dev/null
+++ b/t/disconnect.t
@@ -0,0 +1,65 @@
+use strict;
+use warnings;
+use Test::More qw(no_diag);
+use Test::TCP;
+use IO::Socket::INET;
+use Plack::Loader;
+use Plack::Request;
+use HTTP::Response;
+
+my $app = sub {
+    my $env = shift;
+    my $req = Plack::Request->new($env);
+    my $params = $req->parameters;
+
+    return [
+        200,
+        [ 'Content-Type' => 'text/plain', ],
+        [ $params->{q} ],
+    ];
+};
+
+# test that client disconnection doesn't trigger 400 response
+
+test_tcp(
+    client => sub {
+        my $port = shift;
+
+        # empty request
+        my $sock = IO::Socket::INET->new(
+            Proto => 'tcp',
+            PeerAddr => '127.0.0.1',
+            PeerPort => $port,
+        ) or die "Cannot open client socket: $!";
+        $sock->shutdown(1);
+
+        my $data = join('', <$sock>);
+        $sock->close;
+
+        is($data, '', 'got empty response to empty request')
+            or note explain $data;
+
+        # incomplete headers
+        $sock = IO::Socket::INET->new(
+            Proto => 'tcp',
+            PeerAddr => '127.0.0.1',
+            PeerPort => $port,
+        ) or die "Cannot open client socket: $!";
+
+        print $sock "GET / HTTP/1.0"; # no CRLF
+        $sock->shutdown(1);
+
+        $data = join('', <$sock>);
+        $sock->close;
+
+        is($data, '', 'got empty response to incomplete header request')
+            or note explain $data;
+    },
+    server => sub {
+        my $port = shift;
+        my $server = Plack::Loader->load('Twiggy', port => $port, host => '127.0.0.1');
+        $server->run($app);
+    },
+);
+
+done_testing();