diff --git a/.travis.yml b/.travis.yml
index 849fcda..d0dc010 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,16 +1,5 @@
 language: php
 
-php:
-# - 5.3 # requires old distro
-  - 5.4
-  - 5.5
-  - 5.6
-  - 7.0
-  - 7.1
-  - 7.2
-  - 7.3
-  - hhvm # ignore errors, see below
-
 # lock distro so new future defaults will not break the build
 dist: trusty
 
@@ -18,8 +7,19 @@ matrix:
   include:
     - php: 5.3
       dist: precise
+    - php: 5.4
+    - php: 5.5
+    - php: 5.6
+    - php: 7.0
+    - php: 7.1
+    - php: 7.2
+    - php: 7.3
+    - php: 7.4
+    - php: hhvm-3.18
+      install:
+        - composer require phpunit/phpunit:^5 --dev --no-interaction # requires legacy phpunit
   allow_failures:
-    - php: hhvm
+    - php: hhvm-3.18
 
 sudo: false
 
diff --git a/composer.json b/composer.json
index 45e3d38..4c296fe 100644
--- a/composer.json
+++ b/composer.json
@@ -13,11 +13,14 @@
     "autoload": {
         "psr-4": { "Clue\\React\\Buzz\\": "src/" }
     },
+    "autoload-dev": {
+        "psr-4": { "Clue\\Tests\\React\\Buzz\\": "tests/" }
+    },
     "require": {
         "php": ">=5.3",
         "psr/http-message": "^1.0",
         "react/event-loop": "^1.0 || ^0.5 || ^0.4 || ^0.3",
-        "react/http-client": "^0.5.8",
+        "react/http-client": "^0.5.10",
         "react/promise": "^2.2.1 || ^1.2.1",
         "react/promise-stream": "^1.0 || ^0.1.1",
         "react/promise-timer": "^1.2",
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index e89b186..49fd029 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<phpunit bootstrap="tests/bootstrap.php"
+<phpunit bootstrap="vendor/autoload.php"
          colors="true"
          convertErrorsToExceptions="true"
          convertNoticesToExceptions="true"
diff --git a/tests/BrowserTest.php b/tests/BrowserTest.php
index 8bd6981..8edeb32 100644
--- a/tests/BrowserTest.php
+++ b/tests/BrowserTest.php
@@ -1,7 +1,10 @@
 <?php
 
+namespace Clue\Tests\React\Buzz;
+
 use Clue\React\Block;
 use Clue\React\Buzz\Browser;
+use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\RequestInterface;
 use React\Promise\Promise;
 use RingCentral\Psr7\Uri;
@@ -18,7 +21,7 @@ public function setUp()
         $this->sender = $this->getMockBuilder('Clue\React\Buzz\Io\Transaction')->disableOriginalConstructor()->getMock();
         $this->browser = new Browser($this->loop);
 
-        $ref = new ReflectionProperty($this->browser, 'transaction');
+        $ref = new \ReflectionProperty($this->browser, 'transaction');
         $ref->setAccessible(true);
         $ref->setValue($this->browser, $this->sender);
     }
diff --git a/tests/FunctionalBrowserTest.php b/tests/FunctionalBrowserTest.php
index 8101691..fe4a5f2 100644
--- a/tests/FunctionalBrowserTest.php
+++ b/tests/FunctionalBrowserTest.php
@@ -1,8 +1,11 @@
 <?php
 
+namespace Clue\Tests\React\Buzz;
+
 use Clue\React\Block;
 use Clue\React\Buzz\Browser;
 use Clue\React\Buzz\Message\ResponseException;
+use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\ServerRequestInterface;
 use React\EventLoop\Factory;
 use React\Http\Response;
diff --git a/tests/Io/SenderTest.php b/tests/Io/SenderTest.php
index 95bfed9..be4eaa9 100644
--- a/tests/Io/SenderTest.php
+++ b/tests/Io/SenderTest.php
@@ -1,8 +1,11 @@
 <?php
 
+namespace Clue\Tests\React\Buzz\Io;
+
 use Clue\React\Block;
 use Clue\React\Buzz\Io\Sender;
 use Clue\React\Buzz\Message\ReadableBodyStream;
+use PHPUnit\Framework\TestCase;
 use React\HttpClient\Client as HttpClient;
 use React\HttpClient\RequestData;
 use React\Promise;
@@ -48,7 +51,7 @@ public function testSenderRejectsInvalidUri()
     public function testSenderConnectorRejection()
     {
         $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
-        $connector->expects($this->once())->method('connect')->willReturn(Promise\reject(new RuntimeException('Rejected')));
+        $connector->expects($this->once())->method('connect')->willReturn(Promise\reject(new \RuntimeException('Rejected')));
 
         $sender = new Sender(new HttpClient($this->loop, $connector), $this->getMockBuilder('Clue\React\Buzz\Message\MessageFactory')->getMock());
 
diff --git a/tests/Io/TransactionTest.php b/tests/Io/TransactionTest.php
index c1f608c..284e2df 100644
--- a/tests/Io/TransactionTest.php
+++ b/tests/Io/TransactionTest.php
@@ -1,10 +1,13 @@
 <?php
 
+namespace Clue\Tests\React\Buzz\Io;
+
 use Clue\React\Block;
 use Clue\React\Buzz\Io\Transaction;
 use Clue\React\Buzz\Message\MessageFactory;
 use Clue\React\Buzz\Message\ResponseException;
 use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\RequestInterface;
 use React\EventLoop\Factory;
 use React\Promise;
@@ -25,7 +28,7 @@ public function testWithOptionsReturnsNewInstanceWithChangedOption()
         $this->assertInstanceOf('Clue\React\Buzz\Io\Transaction', $new);
         $this->assertNotSame($transaction, $new);
 
-        $ref = new ReflectionProperty($new, 'followRedirects');
+        $ref = new \ReflectionProperty($new, 'followRedirects');
         $ref->setAccessible(true);
 
         $this->assertFalse($ref->getValue($new));
@@ -39,7 +42,7 @@ public function testWithOptionsDoesNotChangeOriginalInstance()
 
         $transaction->withOptions(array('followRedirects' => false));
 
-        $ref = new ReflectionProperty($transaction, 'followRedirects');
+        $ref = new \ReflectionProperty($transaction, 'followRedirects');
         $ref->setAccessible(true);
 
         $this->assertTrue($ref->getValue($transaction));
@@ -54,7 +57,7 @@ public function testWithOptionsNullValueReturnsNewInstanceWithDefaultOption()
         $transaction = $transaction->withOptions(array('followRedirects' => false));
         $transaction = $transaction->withOptions(array('followRedirects' => null));
 
-        $ref = new ReflectionProperty($transaction, 'followRedirects');
+        $ref = new \ReflectionProperty($transaction, 'followRedirects');
         $ref->setAccessible(true);
 
         $this->assertTrue($ref->getValue($transaction));
diff --git a/tests/Message/MessageFactoryTest.php b/tests/Message/MessageFactoryTest.php
index f0a6f56..f46c933 100644
--- a/tests/Message/MessageFactoryTest.php
+++ b/tests/Message/MessageFactoryTest.php
@@ -1,6 +1,9 @@
 <?php
 
+namespace Clue\Tests\React\Buzz\Message;
+
 use Clue\React\Buzz\Message\MessageFactory;
+use PHPUnit\Framework\TestCase;
 
 class MessageFactoryTest extends TestCase
 {
diff --git a/tests/Message/ReadableBodyStreamTest.php b/tests/Message/ReadableBodyStreamTest.php
index b477159..0ff1cdd 100644
--- a/tests/Message/ReadableBodyStreamTest.php
+++ b/tests/Message/ReadableBodyStreamTest.php
@@ -1,6 +1,9 @@
 <?php
 
+namespace Clue\Tests\React\Buzz\Message;
+
 use Clue\React\Buzz\Message\ReadableBodyStream;
+use PHPUnit\Framework\TestCase;
 use React\Stream\ThroughStream;
 
 class ReadableBodyStreamTest extends TestCase
diff --git a/tests/Message/ResponseExceptionTest.php b/tests/Message/ResponseExceptionTest.php
index 0f00045..ccf4ed5 100644
--- a/tests/Message/ResponseExceptionTest.php
+++ b/tests/Message/ResponseExceptionTest.php
@@ -1,6 +1,9 @@
 <?php
 
+namespace Clue\Tests\React\Buzz\Message;
+
 use Clue\React\Buzz\Message\ResponseException;
+use PHPUnit\Framework\TestCase;
 use RingCentral\Psr7\Response;
 
 class ResponseExceptionTest extends TestCase
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
deleted file mode 100644
index 7cec09c..0000000
--- a/tests/bootstrap.php
+++ /dev/null
@@ -1,11 +0,0 @@
-<?php
-
-use PHPUnit\Framework\TestCase as BaseTestCase;
-
-require __DIR__ . '/../vendor/autoload.php';
-
-error_reporting(-1);
-
-class TestCase extends BaseTestCase
-{
-}