diff --git a/.travis.yml b/.travis.yml
index 9bc9e12..145f909 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,27 +1,23 @@
 language: php
 
-php:
-# - 5.3 # requires old distro, see below
-  - 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
 
-matrix:
+jobs:
   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
   allow_failures:
-    - php: hhvm
-
-sudo: false
+    - php: hhvm-3.18
 
 install:
   - composer install --no-interaction
diff --git a/composer.json b/composer.json
index 7fe0bc3..8b2899b 100644
--- a/composer.json
+++ b/composer.json
@@ -26,6 +26,6 @@
         "react/event-loop": "^1.0 || ^0.5 || ^0.4 || ^0.3",
         "react/promise-timer": "^1.0",
         "clue/block-react": "^1.0",
-        "phpunit/phpunit": "^7.0 || ^6.4 || ^5.7 || ^4.8.35"
+        "phpunit/phpunit": "^9.0 || ^5.7 || ^4.8.35"
     }
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index a40caa1..e68991a 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,11 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<phpunit bootstrap="vendor/autoload.php"
-         colors="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
->
+<phpunit bootstrap="vendor/autoload.php" colors="true">
     <testsuites>
         <testsuite name="PromiseStream Test Suite">
             <directory>./tests/</directory>
diff --git a/tests/CallableStub.php b/tests/CallableStub.php
deleted file mode 100644
index f398c04..0000000
--- a/tests/CallableStub.php
+++ /dev/null
@@ -1,10 +0,0 @@
-<?php
-
-namespace React\Tests\Promise\Stream;
-
-class CallableStub
-{
-    public function __invoke()
-    {
-    }
-}
diff --git a/tests/TestCase.php b/tests/TestCase.php
index f73c2d4..a2a8490 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -53,7 +53,13 @@ protected function expectCallableNever()
      */
     protected function createCallableMock()
     {
-        return $this->getMockBuilder('React\Tests\Promise\Stream\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 expectPromiseResolve($promise)
diff --git a/tests/UnwrapReadableTest.php b/tests/UnwrapReadableTest.php
index a6db4de..59c578f 100644
--- a/tests/UnwrapReadableTest.php
+++ b/tests/UnwrapReadableTest.php
@@ -13,7 +13,10 @@ class UnwrapReadableTest extends TestCase
 {
     private $loop;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpLoop()
     {
         $this->loop = Factory::create();
     }
diff --git a/tests/UnwrapWritableTest.php b/tests/UnwrapWritableTest.php
index 07cc8e3..ecf003c 100644
--- a/tests/UnwrapWritableTest.php
+++ b/tests/UnwrapWritableTest.php
@@ -14,7 +14,10 @@ class UnwrapWritableTest extends TestCase
 {
     private $loop;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpLoop()
     {
         $this->loop = Factory::create();
     }