diff --git a/.travis.yml b/.travis.yml
index be4e6a06..4a99e2a1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,7 @@ language: php
 # lock distro so new future defaults will not break the build
 dist: xenial
 
-matrix:
+jobs:
   include:
     - php: 5.3
       dist: precise
@@ -24,7 +24,7 @@ matrix:
       dist: trusty
       before_install: [] # skip libuv
       install:
-        - composer require phpunit/phpunit:^5 --dev --no-interaction # requires legacy phpunit & skip ./travis-init.sh
+        - composer install # skip ./travis-init.sh
     - name: "Windows"
       os: windows
       language: shell # no built-in php support
@@ -66,8 +66,6 @@ matrix:
     - php: hhvm-3.18
     - os: windows
 
-sudo: false
-
 addons:
   apt:
     packages:
diff --git a/composer.json b/composer.json
index cc6abf06..81cf1017 100644
--- a/composer.json
+++ b/composer.json
@@ -7,7 +7,7 @@
         "php": ">=5.3.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.0 || ^6.4 || ^5.7 || ^4.8.35"
+        "phpunit/phpunit": "^9.0 || ^5.7 || ^4.8.35"
     },
     "suggest": {
         "ext-event": "~1.0 for ExtEventLoop",
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 04d426b5..0e947b87 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,15 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<phpunit backupGlobals="false"
-         backupStaticAttributes="false"
-         colors="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
-         processIsolation="false"
-         stopOnFailure="false"
-         bootstrap="vendor/autoload.php"
->
+<phpunit bootstrap="vendor/autoload.php" colors="true">
     <testsuites>
         <testsuite name="React Test Suite">
             <directory>./tests/</directory>
diff --git a/tests/AbstractLoopTest.php b/tests/AbstractLoopTest.php
index 9b55f959..292ffd1a 100644
--- a/tests/AbstractLoopTest.php
+++ b/tests/AbstractLoopTest.php
@@ -16,7 +16,10 @@ abstract class AbstractLoopTest extends TestCase
 
     const PHP_DEFAULT_CHUNK_SIZE = 8192;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpLoop()
     {
         // It's a timeout, don't set it too low. Travis and other CI systems are slow.
         $this->tickTimeout = 0.02;
@@ -111,6 +114,10 @@ public function testAddWriteStreamTriggersWhenSocketConnectionSucceeds()
 
     public function testAddWriteStreamTriggersWhenSocketConnectionRefused()
     {
+        if (defined('HHVM_VERSION')) {
+            $this->markTestSkipped('Not supported on HHVM');
+        }
+
         // first verify the operating system actually refuses the connection and no firewall is in place
         // use higher timeout because Windows retires multiple times and has a noticeable delay
         // @link https://stackoverflow.com/questions/19440364/why-do-failed-attempts-of-socket-connect-take-1-sec-on-windows
diff --git a/tests/CallableStub.php b/tests/CallableStub.php
deleted file mode 100644
index 913d403a..00000000
--- a/tests/CallableStub.php
+++ /dev/null
@@ -1,10 +0,0 @@
-<?php
-
-namespace React\Tests\EventLoop;
-
-class CallableStub
-{
-    public function __invoke()
-    {
-    }
-}
diff --git a/tests/ExtLibeventLoopTest.php b/tests/ExtLibeventLoopTest.php
index 84970658..32a852b8 100644
--- a/tests/ExtLibeventLoopTest.php
+++ b/tests/ExtLibeventLoopTest.php
@@ -21,7 +21,10 @@ public function createLoop()
         return new ExtLibeventLoop();
     }
 
-    public function tearDown()
+    /**
+     * @after
+     */
+    public function tearDownFile()
     {
         if (file_exists($this->fifoPath)) {
             unlink($this->fifoPath);
diff --git a/tests/StreamSelectLoopTest.php b/tests/StreamSelectLoopTest.php
index 2eb388f0..d6800c5e 100644
--- a/tests/StreamSelectLoopTest.php
+++ b/tests/StreamSelectLoopTest.php
@@ -7,7 +7,10 @@
 
 class StreamSelectLoopTest extends AbstractLoopTest
 {
-    protected function tearDown()
+    /**
+     * @after
+     */
+    protected function tearDownSignalHandlers()
     {
         parent::tearDown();
         if (strncmp($this->getName(false), 'testSignal', 10) === 0 && extension_loaded('pcntl')) {
diff --git a/tests/TestCase.php b/tests/TestCase.php
index dbdd54ce..69b3b227 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -39,7 +39,13 @@ protected function expectCallableNever()
 
     protected function createCallableMock()
     {
-        return $this->getMockBuilder('React\Tests\EventLoop\CallableStub')->getMock();
+        if (method_exists('PHPUnit\Framework\MockObject\MockBuilder', 'addMethods')) {
+            // PHPUnit 9+
+            return $this->getMockBuilder('stdClass')->addMethods(array('__invoke'))->getMock();
+        } else {
+            // legacy PHPUnit 4 - PHPUnit 9
+            return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
+        }
     }
 
     protected function tickLoop(LoopInterface $loop)