diff --git a/composer.json b/composer.json
index 8380a11e..0c6cf7d8 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
     },
     "require-dev": {
         "clue/block-react": "^1.2",
-        "phpunit/phpunit": "^5.0 || ^4.8.10"
+        "phpunit/phpunit": "^6.4 || ^5.7 || ^4.8.35"
     },
     "autoload": {
         "psr-4": { "React\\Dns\\": "src" }
diff --git a/tests/Config/FilesystemFactoryTest.php b/tests/Config/FilesystemFactoryTest.php
index 718c11fc..bb9eac75 100644
--- a/tests/Config/FilesystemFactoryTest.php
+++ b/tests/Config/FilesystemFactoryTest.php
@@ -2,9 +2,10 @@
 
 namespace React\Test\Dns\Config;
 
+use PHPUnit\Framework\TestCase;
 use React\Dns\Config\FilesystemFactory;
 
-class FilesystemFactoryTest extends \PHPUnit_Framework_TestCase
+class FilesystemFactoryTest extends TestCase
 {
     /** @test */
     public function parseEtcResolvConfShouldParseCorrectly()
diff --git a/tests/Model/MessageTest.php b/tests/Model/MessageTest.php
index 46528273..53d6b28f 100644
--- a/tests/Model/MessageTest.php
+++ b/tests/Model/MessageTest.php
@@ -2,10 +2,11 @@
 
 namespace React\Tests\Dns\Model;
 
+use PHPUnit\Framework\TestCase;
 use React\Dns\Query\Query;
 use React\Dns\Model\Message;
 
-class MessageTest extends \PHPUnit_Framework_TestCase
+class MessageTest extends TestCase
 {
     public function testCreateRequestDesiresRecusion()
     {
diff --git a/tests/Protocol/BinaryDumperTest.php b/tests/Protocol/BinaryDumperTest.php
index dffc4b5b..bf60ca97 100644
--- a/tests/Protocol/BinaryDumperTest.php
+++ b/tests/Protocol/BinaryDumperTest.php
@@ -2,10 +2,11 @@
 
 namespace React\Tests\Dns\Protocol;
 
+use PHPUnit\Framework\TestCase;
 use React\Dns\Protocol\BinaryDumper;
 use React\Dns\Model\Message;
 
-class BinaryDumperTest extends \PHPUnit_Framework_TestCase
+class BinaryDumperTest extends TestCase
 {
     public function testRequestToBinary()
     {
diff --git a/tests/Protocol/ParserTest.php b/tests/Protocol/ParserTest.php
index 97b07272..195fad24 100644
--- a/tests/Protocol/ParserTest.php
+++ b/tests/Protocol/ParserTest.php
@@ -2,10 +2,11 @@
 
 namespace React\Tests\Dns\Protocol;
 
+use PHPUnit\Framework\TestCase;
 use React\Dns\Protocol\Parser;
 use React\Dns\Model\Message;
 
-class ParserTest extends \PHPUnit_Framework_TestCase
+class ParserTest extends TestCase
 {
     public function setUp()
     {
diff --git a/tests/Query/RecordBagTest.php b/tests/Query/RecordBagTest.php
index 48353531..83b89344 100644
--- a/tests/Query/RecordBagTest.php
+++ b/tests/Query/RecordBagTest.php
@@ -2,11 +2,12 @@
 
 namespace React\Tests\Dns\Query;
 
+use PHPUnit\Framework\TestCase;
 use React\Dns\Query\RecordBag;
 use React\Dns\Model\Message;
 use React\Dns\Model\Record;
 
-class RecordBagTest extends \PHPUnit_Framework_TestCase
+class RecordBagTest extends TestCase
 {
     /**
     * @covers React\Dns\Query\RecordBag
diff --git a/tests/Query/RecordCacheTest.php b/tests/Query/RecordCacheTest.php
index 4500c724..399fbe8a 100644
--- a/tests/Query/RecordCacheTest.php
+++ b/tests/Query/RecordCacheTest.php
@@ -2,6 +2,7 @@
 
 namespace React\Tests\Dns\Query;
 
+use PHPUnit\Framework\TestCase;
 use React\Cache\ArrayCache;
 use React\Dns\Model\Message;
 use React\Dns\Model\Record;
@@ -9,7 +10,7 @@
 use React\Dns\Query\Query;
 use React\Promise\PromiseInterface;
 
-class RecordCacheTest extends \PHPUnit_Framework_TestCase
+class RecordCacheTest extends TestCase
 {
     /**
     * @covers React\Dns\Query\RecordCache
diff --git a/tests/Resolver/ResolveAliasesTest.php b/tests/Resolver/ResolveAliasesTest.php
index 7ffa082e..b5175e3e 100644
--- a/tests/Resolver/ResolveAliasesTest.php
+++ b/tests/Resolver/ResolveAliasesTest.php
@@ -2,12 +2,13 @@
 
 namespace React\Tests\Dns\Resolver;
 
+use PHPUnit\Framework\TestCase;
 use React\Dns\Resolver\Resolver;
 use React\Dns\Query\Query;
 use React\Dns\Model\Message;
 use React\Dns\Model\Record;
 
-class ResolveAliasesTest extends \PHPUnit_Framework_TestCase
+class ResolveAliasesTest extends TestCase
 {
     /**
      * @covers React\Dns\Resolver\Resolver::resolveAliases
diff --git a/tests/TestCase.php b/tests/TestCase.php
index 620bfaa1..a5a22bfd 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -2,7 +2,9 @@
 
 namespace React\Tests\Dns;
 
-abstract class TestCase extends \PHPUnit_Framework_TestCase
+use PHPUnit\Framework\TestCase as BaseTestCase;
+
+abstract class TestCase extends BaseTestCase
 {
     protected function expectCallableOnce()
     {
@@ -39,4 +41,21 @@ protected function createCallableMock()
     {
         return $this->getMockBuilder('React\Tests\Dns\CallableStub')->getMock();
     }
+
+    public function setExpectedException($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);
+         }
+     }
 }