diff --git a/.travis.yml b/.travis.yml
index d0dc010..0a5430e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,8 +16,6 @@ matrix:
     - 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-3.18
 
diff --git a/composer.json b/composer.json
index 313bd03..8749123 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,7 @@
         "clue/http-proxy-react": "^1.3",
         "clue/reactphp-ssh-proxy": "^1.0",
         "clue/socks-react": "^1.0",
-        "phpunit/phpunit": "^7.0 || ^6.4 || ^5.7 || ^4.8.35",
+        "phpunit/phpunit": "^9.0 || ^5.7 || ^4.8.35",
         "react/http": "^0.8"
     }
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 8bb54bb..e580744 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -11,4 +11,4 @@
             <directory>./src/</directory>
         </whitelist>
     </filter>
-</phpunit>
\ No newline at end of file
+</phpunit>
diff --git a/tests/BrowserTest.php b/tests/BrowserTest.php
index fd7f250..ed3c273 100644
--- a/tests/BrowserTest.php
+++ b/tests/BrowserTest.php
@@ -4,7 +4,6 @@
 
 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;
@@ -15,7 +14,10 @@ class BrowserTest extends TestCase
     private $sender;
     private $browser;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpBrowser()
     {
         $this->loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
         $this->sender = $this->getMockBuilder('Clue\React\Buzz\Io\Transaction')->disableOriginalConstructor()->getMock();
@@ -226,7 +228,6 @@ public function provideOtherBaseUris()
     /**
      * @param string $other
      * @dataProvider provideOtherBaseUris
-     * @expectedException UnexpectedValueException
      */
     public function testRequestingUrlsNotBelowBaseWillRejectBeforeSending($other)
     {
@@ -234,14 +235,13 @@ public function testRequestingUrlsNotBelowBaseWillRejectBeforeSending($other)
 
         $this->sender->expects($this->never())->method('send');
 
+        $this->setExpectedException('UnexpectedValueException');
         Block\await($browser->get($other), $this->loop);
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testWithBaseUriNotAbsoluteFails()
     {
+        $this->setExpectedException('InvalidArgumentException');
         $this->browser->withBase('hello');
     }
 
@@ -271,11 +271,9 @@ public function testWithProtocolVersionFollowedBySubmitRequestSendsRequestWithPr
         $this->browser->submit('http://example.com/', array());
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testWithProtocolVersionInvalidThrows()
     {
+        $this->setExpectedException('InvalidArgumentException');
         $this->browser->withProtocolVersion('1.2');
     }
 
@@ -291,19 +289,4 @@ public function testCancelGetRequestShouldCancelUnderlyingSocketConnection()
         $promise = $this->browser->get('http://example.com/');
         $promise->cancel();
     }
-
-    protected function expectCallableOnce()
-    {
-        $mock = $this->createCallableMock();
-        $mock
-            ->expects($this->once())
-            ->method('__invoke');
-
-        return $mock;
-    }
-
-    protected function createCallableMock()
-    {
-        return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
-    }
 }
diff --git a/tests/FunctionalBrowserTest.php b/tests/FunctionalBrowserTest.php
index 398b311..35c7bf7 100644
--- a/tests/FunctionalBrowserTest.php
+++ b/tests/FunctionalBrowserTest.php
@@ -5,7 +5,6 @@
 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;
@@ -23,7 +22,10 @@ class FunctionalBrowserTest extends TestCase
     private $browser;
     private $base;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpBrowserAndServer()
     {
         $this->loop = $loop = Factory::create();
         $this->browser = new Browser($this->loop);
@@ -143,20 +145,15 @@ public function testSimpleRequest()
         Block\await($this->browser->get($this->base . 'get'), $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testCancelGetRequestWillRejectRequest()
     {
         $promise = $this->browser->get($this->base . 'get');
         $promise->cancel();
 
+        $this->setExpectedException('RuntimeException');
         Block\await($promise, $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testCancelSendWithPromiseFollowerWillRejectRequest()
     {
         $promise = $this->browser->send(new Request('GET', $this->base . 'get'))->then(function () {
@@ -164,14 +161,13 @@ public function testCancelSendWithPromiseFollowerWillRejectRequest()
         });
         $promise->cancel();
 
+        $this->setExpectedException('RuntimeException');
         Block\await($promise, $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testRequestWithoutAuthenticationFails()
     {
+        $this->setExpectedException('RuntimeException');
         Block\await($this->browser->get($this->base . 'basic-auth/user/pass'), $this->loop);
     }
 
@@ -214,10 +210,6 @@ public function testRedirectFromPageWithInvalidAuthToPageWithCorrectAuthenticati
         Block\await($this->browser->get($base . 'redirect-to?url=' . urlencode($target)), $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage Request cancelled
-     */
     public function testCancelRedirectedRequestShouldReject()
     {
         $promise = $this->browser->get($this->base . 'redirect-to?url=delay%2F10');
@@ -226,30 +218,25 @@ public function testCancelRedirectedRequestShouldReject()
             $promise->cancel();
         });
 
+        $this->setExpectedException('RuntimeException', 'Request cancelled');
         Block\await($promise, $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage Request timed out after 0.1 seconds
-     */
     public function testTimeoutDelayedResponseShouldReject()
     {
         $promise = $this->browser->withOptions(array('timeout' => 0.1))->get($this->base . 'delay/10');
 
+        $this->setExpectedException('RuntimeException', 'Request timed out after 0.1 seconds');
         Block\await($promise, $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage Request timed out after 0.1 seconds
-     */
     public function testTimeoutDelayedResponseAfterStreamingRequestShouldReject()
     {
         $stream = new ThroughStream();
         $promise = $this->browser->withOptions(array('timeout' => 0.1))->post($this->base . 'delay/10', array(), $stream);
         $stream->end();
 
+        $this->setExpectedException('RuntimeException', 'Request timed out after 0.1 seconds');
         Block\await($promise, $this->loop);
     }
 
@@ -287,13 +274,11 @@ public function testNotFollowingRedirectsResolvesWithRedirectResult()
         Block\await($browser->get($this->base . 'redirect-to?url=get'), $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testRejectingRedirectsRejects()
     {
         $browser = $this->browser->withOptions(array('maxRedirects' => 0));
 
+        $this->setExpectedException('RuntimeException');
         Block\await($browser->get($this->base . 'redirect-to?url=get'), $this->loop);
     }
 
@@ -320,7 +305,6 @@ public function testCanAccessHttps()
 
     /**
      * @group online
-     * @expectedException RuntimeException
      */
     public function testVerifyPeerEnabledForBadSslRejects()
     {
@@ -336,6 +320,7 @@ public function testVerifyPeerEnabledForBadSslRejects()
 
         $browser = new Browser($this->loop, $connector);
 
+        $this->setExpectedException('RuntimeException');
         Block\await($browser->get('https://self-signed.badssl.com/'), $this->loop);
     }
 
@@ -362,10 +347,10 @@ public function testVerifyPeerDisabledForBadSslResolves()
 
     /**
      * @group online
-     * @expectedException RuntimeException
      */
     public function testInvalidPort()
     {
+        $this->setExpectedException('RuntimeException');
         Block\await($this->browser->get('http://www.google.com:443/'), $this->loop);
     }
 
diff --git a/tests/Io/ChunkedEncoderTest.php b/tests/Io/ChunkedEncoderTest.php
index c449033..8376dff 100644
--- a/tests/Io/ChunkedEncoderTest.php
+++ b/tests/Io/ChunkedEncoderTest.php
@@ -3,7 +3,7 @@
 namespace Clue\Tests\React\Buzz\Io;
 
 use Clue\React\Buzz\Io\ChunkedEncoder;
-use PHPUnit\Framework\TestCase;
+use Clue\Tests\React\Buzz\TestCase;
 use React\Stream\ThroughStream;
 
 class ChunkedEncoderTest extends TestCase
@@ -11,7 +11,10 @@ class ChunkedEncoderTest extends TestCase
     private $input;
     private $chunkedStream;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpStream()
     {
         $this->input = new ThroughStream();
         $this->chunkedStream = new ChunkedEncoder($this->input);
@@ -81,40 +84,4 @@ public function testPipeStream()
 
         $this->assertSame($dest, $ret);
     }
-
-    protected function expectCallableOnce()
-    {
-        $mock = $this->createCallableMock();
-        $mock
-            ->expects($this->once())
-            ->method('__invoke');
-
-        return $mock;
-    }
-
-    protected function expectCallableOnceWith($value)
-    {
-        $mock = $this->createCallableMock();
-        $mock
-            ->expects($this->once())
-            ->method('__invoke')
-            ->with($value);
-
-        return $mock;
-    }
-
-    protected function expectCallableNever()
-    {
-        $mock = $this->createCallableMock();
-        $mock
-            ->expects($this->never())
-            ->method('__invoke');
-
-        return $mock;
-    }
-
-    protected function createCallableMock()
-    {
-        return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
-    }
 }
diff --git a/tests/Io/SenderTest.php b/tests/Io/SenderTest.php
index d260b65..c855e9e 100644
--- a/tests/Io/SenderTest.php
+++ b/tests/Io/SenderTest.php
@@ -5,7 +5,7 @@
 use Clue\React\Block;
 use Clue\React\Buzz\Io\Sender;
 use Clue\React\Buzz\Message\ReadableBodyStream;
-use PHPUnit\Framework\TestCase;
+use Clue\Tests\React\Buzz\TestCase;
 use React\HttpClient\Client as HttpClient;
 use React\HttpClient\RequestData;
 use React\Promise;
@@ -16,7 +16,10 @@ class SenderTest extends TestCase
 {
     private $loop;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpLoop()
     {
         $this->loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
     }
@@ -28,9 +31,6 @@ public function testCreateFromLoop()
         $this->assertInstanceOf('Clue\React\Buzz\Io\Sender', $sender);
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testSenderRejectsInvalidUri()
     {
         $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
@@ -42,12 +42,10 @@ public function testSenderRejectsInvalidUri()
 
         $promise = $sender->send($request);
 
+        $this->setExpectedException('InvalidArgumentException');
         Block\await($promise, $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testSenderConnectorRejection()
     {
         $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
@@ -59,6 +57,7 @@ public function testSenderConnectorRejection()
 
         $promise = $sender->send($request);
 
+        $this->setExpectedException('RuntimeException');
         Block\await($promise, $this->loop);
     }
 
@@ -303,9 +302,6 @@ public function testSendCustomMethodWithExplicitContentLengthZeroWillBePassedAsI
         $sender->send($request);
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testCancelRequestWillCancelConnector()
     {
         $promise = new \React\Promise\Promise(function () { }, function () {
@@ -322,12 +318,10 @@ public function testCancelRequestWillCancelConnector()
         $promise = $sender->send($request);
         $promise->cancel();
 
+        $this->setExpectedException('RuntimeException');
         Block\await($promise, $this->loop);
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testCancelRequestWillCloseConnection()
     {
         $connection = $this->getMockBuilder('React\Socket\ConnectionInterface')->getMock();
@@ -343,6 +337,7 @@ public function testCancelRequestWillCloseConnection()
         $promise = $sender->send($request);
         $promise->cancel();
 
+        $this->setExpectedException('RuntimeException');
         Block\await($promise, $this->loop);
     }
 
diff --git a/tests/Io/TransactionTest.php b/tests/Io/TransactionTest.php
index e47c362..18ada59 100644
--- a/tests/Io/TransactionTest.php
+++ b/tests/Io/TransactionTest.php
@@ -6,8 +6,8 @@
 use Clue\React\Buzz\Io\Transaction;
 use Clue\React\Buzz\Message\MessageFactory;
 use Clue\React\Buzz\Message\ResponseException;
+use Clue\Tests\React\Buzz\TestCase;
 use PHPUnit\Framework\MockObject\MockObject;
-use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\RequestInterface;
 use React\EventLoop\Factory;
 use React\Promise;
@@ -409,9 +409,6 @@ public function testReceivingStreamingBodyWillResolveWithBufferedResponseByDefau
         $this->assertEquals('hello world', (string)$response->getBody());
     }
 
-    /**
-     * @expectedException RuntimeException
-     */
     public function testCancelBufferingResponseWillCloseStreamAndReject()
     {
         $messageFactory = new MessageFactory();
@@ -432,6 +429,7 @@ public function testCancelBufferingResponseWillCloseStreamAndReject()
         $promise = $transaction->send($request);
         $promise->cancel();
 
+        $this->setExpectedException('RuntimeException');
         Block\await($promise, $loop, 0.001);
     }
 
@@ -813,30 +811,4 @@ private function makeSenderMock()
     {
         return $this->getMockBuilder('Clue\React\Buzz\Io\Sender')->disableOriginalConstructor()->getMock();
     }
-
-    protected function expectCallableOnce()
-    {
-        $mock = $this->createCallableMock();
-        $mock
-            ->expects($this->once())
-            ->method('__invoke');
-
-        return $mock;
-    }
-
-    protected function expectCallableOnceWith($value)
-    {
-        $mock = $this->createCallableMock();
-        $mock
-            ->expects($this->once())
-            ->method('__invoke')
-            ->with($value);
-
-        return $mock;
-    }
-
-    protected function createCallableMock()
-    {
-        return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
-    }
 }
diff --git a/tests/Message/MessageFactoryTest.php b/tests/Message/MessageFactoryTest.php
index ad86bd0..bc8a462 100644
--- a/tests/Message/MessageFactoryTest.php
+++ b/tests/Message/MessageFactoryTest.php
@@ -9,7 +9,10 @@ class MessageFactoryTest extends TestCase
 {
     private $messageFactory;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpMessageFactory()
     {
         $this->messageFactory = new MessageFactory();
     }
diff --git a/tests/Message/ReadableBodyStreamTest.php b/tests/Message/ReadableBodyStreamTest.php
index 3990cb7..203963b 100644
--- a/tests/Message/ReadableBodyStreamTest.php
+++ b/tests/Message/ReadableBodyStreamTest.php
@@ -3,7 +3,7 @@
 namespace Clue\Tests\React\Buzz\Message;
 
 use Clue\React\Buzz\Message\ReadableBodyStream;
-use PHPUnit\Framework\TestCase;
+use Clue\Tests\React\Buzz\TestCase;
 use React\Stream\ThroughStream;
 
 class ReadableBodyStreamTest extends TestCase
@@ -11,7 +11,10 @@ class ReadableBodyStreamTest extends TestCase
     private $input;
     private $stream;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpStream()
     {
         $this->input = $this->getMockBuilder('React\Stream\ReadableStreamInterface')->getMock();
         $this->stream = new ReadableBodyStream($this->input);
@@ -183,11 +186,9 @@ public function testPointlessTostringReturnsEmptyString()
         $this->assertEquals('', (string)$this->stream);
     }
 
-    /**
-     * @expectedException BadMethodCallException
-     */
     public function testPointlessDetachThrows()
     {
+        $this->setExpectedException('BadMethodCallException');
         $this->stream->detach();
     }
 
@@ -196,11 +197,9 @@ public function testPointlessGetSizeReturnsNull()
         $this->assertEquals(null, $this->stream->getSize());
     }
 
-    /**
-     * @expectedException BadMethodCallException
-     */
     public function testPointlessTellThrows()
     {
+        $this->setExpectedException('BadMethodCallException');
         $this->stream->tell();
     }
 
@@ -209,19 +208,15 @@ public function testPointlessIsSeekableReturnsFalse()
         $this->assertEquals(false, $this->stream->isSeekable());
     }
 
-    /**
-     * @expectedException BadMethodCallException
-     */
     public function testPointlessSeekThrows()
     {
+        $this->setExpectedException('BadMethodCallException');
         $this->stream->seek(0);
     }
 
-    /**
-     * @expectedException BadMethodCallException
-     */
     public function testPointlessRewindThrows()
     {
+        $this->setExpectedException('BadMethodCallException');
         $this->stream->rewind();
     }
 
@@ -230,27 +225,21 @@ public function testPointlessIsWritableReturnsFalse()
         $this->assertEquals(false, $this->stream->isWritable());
     }
 
-    /**
-     * @expectedException BadMethodCallException
-     */
     public function testPointlessWriteThrows()
     {
+        $this->setExpectedException('BadMethodCallException');
         $this->stream->write('');
     }
 
-    /**
-     * @expectedException BadMethodCallException
-     */
     public function testPointlessReadThrows()
     {
+        $this->setExpectedException('BadMethodCallException');
         $this->stream->read(8192);
     }
 
-    /**
-     * @expectedException BadMethodCallException
-     */
     public function testPointlessGetContentsThrows()
     {
+        $this->setExpectedException('BadMethodCallException');
         $this->stream->getContents();
     }
 
diff --git a/tests/TestCase.php b/tests/TestCase.php
new file mode 100644
index 0000000..7f1324f
--- /dev/null
+++ b/tests/TestCase.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Clue\Tests\React\Buzz;
+
+class TestCase extends \PHPUnit\Framework\TestCase
+{
+    public function setExpectedException($exception, $exceptionMessage = '', $exceptionCode = null)
+    {
+        if (method_exists($this, 'expectException')) {
+            // PHPUnit 5+
+            $this->expectException($exception);
+            if ($exceptionMessage !== '') {
+                $this->expectExceptionMessage($exceptionMessage);
+            }
+            if ($exceptionCode !== null) {
+                $this->expectExceptionCode($exceptionCode);
+            }
+        } else {
+            // legacy PHPUnit 4
+            parent::setExpectedException($exception, $exceptionMessage, $exceptionCode);
+        }
+    }
+
+    protected function expectCallableOnce()
+    {
+        $mock = $this->createCallableMock();
+        $mock
+            ->expects($this->once())
+            ->method('__invoke');
+
+        return $mock;
+    }
+
+    protected function expectCallableOnceWith($value)
+    {
+        $mock = $this->createCallableMock();
+        $mock
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($value);
+
+        return $mock;
+    }
+
+    protected function expectCallableNever()
+    {
+        $mock = $this->createCallableMock();
+        $mock
+            ->expects($this->never())
+            ->method('__invoke');
+
+        return $mock;
+    }
+
+    protected function createCallableMock()
+    {
+        return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
+    }
+}