diff --git a/composer.json b/composer.json
index 48a9073e..9740c9a3 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
     },
     "require-dev": {
         "clue/block-react": "^1.1",
-        "phpunit/phpunit": "~4.8"
+        "phpunit/phpunit": "^5.0 || ^4.8"
     },
     "autoload": {
         "psr-4": {
diff --git a/tests/DnsConnectorTest.php b/tests/DnsConnectorTest.php
index c33850b1..3c94c390 100644
--- a/tests/DnsConnectorTest.php
+++ b/tests/DnsConnectorTest.php
@@ -13,7 +13,7 @@ class DnsConnectorTest extends TestCase
 
     public function setUp()
     {
-        $this->tcp = $this->getMock('React\Socket\ConnectorInterface');
+        $this->tcp = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
         $this->resolver = $this->getMockBuilder('React\Dns\Resolver\Resolver')->disableOriginalConstructor()->getMock();
 
         $this->connector = new DnsConnector($this->tcp, $this->resolver);
diff --git a/tests/LimitingServerTest.php b/tests/LimitingServerTest.php
index 0484a147..2cc9a581 100644
--- a/tests/LimitingServerTest.php
+++ b/tests/LimitingServerTest.php
@@ -75,7 +75,7 @@ public function testCloseWillBePassedThroughToTcpServer()
 
     public function testSocketErrorWillBeForwarded()
     {
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $tcp = new TcpServer(0, $loop);
 
@@ -90,7 +90,7 @@ public function testSocketConnectionWillBeForwarded()
     {
         $connection = $this->getMockBuilder('React\Socket\ConnectionInterface')->getMock();
 
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $tcp = new TcpServer(0, $loop);
 
@@ -110,7 +110,7 @@ public function testSocketConnectionWillBeClosedOnceLimitIsReached()
         $second = $this->getMockBuilder('React\Socket\ConnectionInterface')->getMock();
         $second->expects($this->once())->method('close');
 
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $tcp = new TcpServer(0, $loop);
 
@@ -124,7 +124,7 @@ public function testSocketConnectionWillBeClosedOnceLimitIsReached()
 
     public function testPausingServerWillBePausedOnceLimitIsReached()
     {
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
         $loop->expects($this->once())->method('addReadStream');
         $loop->expects($this->once())->method('removeReadStream');
 
diff --git a/tests/SecureConnectorTest.php b/tests/SecureConnectorTest.php
index e22c3c75..0b3a7025 100644
--- a/tests/SecureConnectorTest.php
+++ b/tests/SecureConnectorTest.php
@@ -17,8 +17,8 @@ public function setUp()
             $this->markTestSkipped('Not supported on your platform (outdated HHVM?)');
         }
 
-        $this->loop = $this->getMock('React\EventLoop\LoopInterface');
-        $this->tcp = $this->getMock('React\Socket\ConnectorInterface');
+        $this->loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
+        $this->tcp = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
         $this->connector = new SecureConnector($this->tcp, $this->loop);
     }
 
diff --git a/tests/SecureServerTest.php b/tests/SecureServerTest.php
index f28a4da7..798e7b4e 100644
--- a/tests/SecureServerTest.php
+++ b/tests/SecureServerTest.php
@@ -19,7 +19,7 @@ public function testGetAddressWillBePassedThroughToTcpServer()
         $tcp = $this->getMockBuilder('React\Socket\ServerInterface')->getMock();
         $tcp->expects($this->once())->method('getAddress')->willReturn('127.0.0.1:1234');
 
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $server = new SecureServer($tcp, $loop, array());
 
@@ -31,7 +31,7 @@ public function testPauseWillBePassedThroughToTcpServer()
         $tcp = $this->getMockBuilder('React\Socket\ServerInterface')->getMock();
         $tcp->expects($this->once())->method('pause');
 
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $server = new SecureServer($tcp, $loop, array());
 
@@ -43,7 +43,7 @@ public function testResumeWillBePassedThroughToTcpServer()
         $tcp = $this->getMockBuilder('React\Socket\ServerInterface')->getMock();
         $tcp->expects($this->once())->method('resume');
 
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $server = new SecureServer($tcp, $loop, array());
 
@@ -55,7 +55,7 @@ public function testCloseWillBePassedThroughToTcpServer()
         $tcp = $this->getMockBuilder('React\Socket\ServerInterface')->getMock();
         $tcp->expects($this->once())->method('close');
 
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $server = new SecureServer($tcp, $loop, array());
 
@@ -64,7 +64,7 @@ public function testCloseWillBePassedThroughToTcpServer()
 
     public function testConnectionWillBeEndedWithErrorIfItIsNotAStream()
     {
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $tcp = new TcpServer(0, $loop);
 
@@ -80,7 +80,7 @@ public function testConnectionWillBeEndedWithErrorIfItIsNotAStream()
 
     public function testSocketErrorWillBeForwarded()
     {
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $tcp = new TcpServer(0, $loop);
 
diff --git a/tests/TcpConnectorTest.php b/tests/TcpConnectorTest.php
index 9d824ce7..80e80af2 100644
--- a/tests/TcpConnectorTest.php
+++ b/tests/TcpConnectorTest.php
@@ -141,7 +141,7 @@ public function connectionToIp6TcpServerShouldSucceed()
     /** @test */
     public function connectionToHostnameShouldFailImmediately()
     {
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $connector = new TcpConnector($loop);
         $connector->connect('www.google.com:80')->then(
@@ -153,7 +153,7 @@ public function connectionToHostnameShouldFailImmediately()
     /** @test */
     public function connectionToInvalidPortShouldFailImmediately()
     {
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $connector = new TcpConnector($loop);
         $connector->connect('255.255.255.255:12345678')->then(
@@ -165,7 +165,7 @@ public function connectionToInvalidPortShouldFailImmediately()
     /** @test */
     public function connectionToInvalidSchemeShouldFailImmediately()
     {
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $connector = new TcpConnector($loop);
         $connector->connect('tls://google.com:443')->then(
@@ -179,7 +179,7 @@ public function connectionWithInvalidContextShouldFailImmediately()
     {
         $this->markTestIncomplete();
 
-        $loop = $this->getMock('React\EventLoop\LoopInterface');
+        $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
         $connector = new TcpConnector($loop, array('bindto' => 'invalid.invalid:123456'));
         $connector->connect('127.0.0.1:80')->then(
diff --git a/tests/TestCase.php b/tests/TestCase.php
index 3360e836..81e925d6 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -52,7 +52,7 @@ protected function expectCallableNever()
 
     protected function createCallableMock()
     {
-        return $this->getMock('React\Tests\Socket\Stub\CallableStub');
+        return $this->getMockBuilder('React\Tests\Socket\Stub\CallableStub')->getMock();
     }
 
     protected function buffer(ReadableStreamInterface $stream, LoopInterface $loop, $timeout)
diff --git a/tests/TimeoutConnectorTest.php b/tests/TimeoutConnectorTest.php
index 333e8bfd..64787d93 100644
--- a/tests/TimeoutConnectorTest.php
+++ b/tests/TimeoutConnectorTest.php
@@ -12,7 +12,7 @@ public function testRejectsOnTimeout()
     {
         $promise = new Promise\Promise(function () { });
 
-        $connector = $this->getMock('React\Socket\ConnectorInterface');
+        $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
         $connector->expects($this->once())->method('connect')->with('google.com:80')->will($this->returnValue($promise));
 
         $loop = Factory::create();
@@ -31,7 +31,7 @@ public function testRejectsWhenConnectorRejects()
     {
         $promise = Promise\reject(new \RuntimeException());
 
-        $connector = $this->getMock('React\Socket\ConnectorInterface');
+        $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
         $connector->expects($this->once())->method('connect')->with('google.com:80')->will($this->returnValue($promise));
 
         $loop = Factory::create();
@@ -50,7 +50,7 @@ public function testResolvesWhenConnectorResolves()
     {
         $promise = Promise\resolve();
 
-        $connector = $this->getMock('React\Socket\ConnectorInterface');
+        $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
         $connector->expects($this->once())->method('connect')->with('google.com:80')->will($this->returnValue($promise));
 
         $loop = Factory::create();
@@ -69,7 +69,7 @@ public function testRejectsAndCancelsPendingPromiseOnTimeout()
     {
         $promise = new Promise\Promise(function () { }, $this->expectCallableOnce());
 
-        $connector = $this->getMock('React\Socket\ConnectorInterface');
+        $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
         $connector->expects($this->once())->method('connect')->with('google.com:80')->will($this->returnValue($promise));
 
         $loop = Factory::create();
@@ -88,7 +88,7 @@ public function testCancelsPendingPromiseOnCancel()
     {
         $promise = new Promise\Promise(function () { }, function () { throw new \Exception(); });
 
-        $connector = $this->getMock('React\Socket\ConnectorInterface');
+        $connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
         $connector->expects($this->once())->method('connect')->with('google.com:80')->will($this->returnValue($promise));
 
         $loop = Factory::create();
diff --git a/tests/UnixConnectorTest.php b/tests/UnixConnectorTest.php
index 1c86f616..5c988c1a 100644
--- a/tests/UnixConnectorTest.php
+++ b/tests/UnixConnectorTest.php
@@ -13,7 +13,7 @@ class UnixConnectorTest extends TestCase
 
     public function setUp()
     {
-        $this->loop = $this->getMock('React\EventLoop\LoopInterface');
+        $this->loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
         $this->connector = new UnixConnector($this->loop);
     }