diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..0925d33
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,6 @@
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/.travis.yml export-ignore
+/examples/ export-ignore
+/phpunit.xml.dist export-ignore
+/tests/ export-ignore
diff --git a/composer.json b/composer.json
index c54b3ec..d47888c 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
         "react/stream": "^1.0 || ^0.7 || ^0.6"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.0 || ^4.8",
+        "phpunit/phpunit": "^7.0 || ^6.0",
         "react/event-loop": "^1.0 || ^0.5 || ^0.4 || ^0.3"
     },
     "suggest": {
@@ -24,5 +24,8 @@
     },
     "autoload": {
         "psr-4": { "Clue\\React\\Zlib\\": "src/" }
+    },
+    "autoload-dev": {
+        "psr-4": { "Clue\\Tests\\React\\Zlib\\": "tests/" }
     }
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 4e6ec6c..a30c9fd 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,11 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<phpunit bootstrap="tests/bootstrap.php"
-         colors="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
->
+<phpunit bootstrap="vendor/autoload.php" colors="true">
     <testsuites>
         <testsuite name="zlib React Test Suite">
             <directory>./tests/</directory>
diff --git a/tests/CompressorTest.php b/tests/CompressorTest.php
index 1d93db2..246eada 100644
--- a/tests/CompressorTest.php
+++ b/tests/CompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Compressor;
 
 class CompressorTest extends TestCase
diff --git a/tests/DecompressorTest.php b/tests/DecompressorTest.php
index a3aa264..f075127 100644
--- a/tests/DecompressorTest.php
+++ b/tests/DecompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Decompressor;
 
 class DecompressorTest extends TestCase
diff --git a/tests/DeflateDecompressorTest.php b/tests/DeflateDecompressorTest.php
index 9100a5a..8d47d78 100644
--- a/tests/DeflateDecompressorTest.php
+++ b/tests/DeflateDecompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Decompressor;
 
 class DeflateDecompressorTest extends TestCase
diff --git a/tests/DelateCompressorTest.php b/tests/DelateCompressorTest.php
index cc8af6a..3fa2a70 100644
--- a/tests/DelateCompressorTest.php
+++ b/tests/DelateCompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Compressor;
 
 class DeflateCompressorTest extends TestCase
diff --git a/tests/FunctionalExamplesTest.php b/tests/FunctionalExamplesTest.php
index e0431e7..490d5c3 100644
--- a/tests/FunctionalExamplesTest.php
+++ b/tests/FunctionalExamplesTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 class FunctionalExamplesTest extends TestCase
 {
     public function setUp()
diff --git a/tests/GzipCompressorTest.php b/tests/GzipCompressorTest.php
index 28fa560..91d4669 100644
--- a/tests/GzipCompressorTest.php
+++ b/tests/GzipCompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Compressor;
 
 class GzipCompressorTest extends TestCase
diff --git a/tests/GzipDecompressorTest.php b/tests/GzipDecompressorTest.php
index 1ebaffd..37fad7e 100644
--- a/tests/GzipDecompressorTest.php
+++ b/tests/GzipDecompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Decompressor;
 
 class GzipDecompressorTest extends TestCase
diff --git a/tests/bootstrap.php b/tests/TestCase.php
similarity index 67%
rename from tests/bootstrap.php
rename to tests/TestCase.php
index 05c2338..d9e084b 100644
--- a/tests/bootstrap.php
+++ b/tests/TestCase.php
@@ -1,8 +1,8 @@
 <?php
 
-require __DIR__ . '/../vendor/autoload.php';
+namespace Clue\Tests\React\Zlib;
 
-class TestCase extends PHPUnit_Framework_TestCase
+class TestCase extends \PHPUnit\Framework\TestCase
 {
     protected function expectCallableOnce()
     {
@@ -37,18 +37,8 @@ protected function expectCallableNever()
         return $mock;
     }
 
-    /**
-     * @link https://github.com/reactphp/react/blob/master/tests/React/Tests/Socket/TestCase.php (taken from reactphp/react)
-     */
     protected function createCallableMock()
     {
-        return $this->getMockBuilder('CallableStub')->getMock();
-    }
-}
-
-class CallableStub
-{
-    public function __invoke()
-    {
+        return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
     }
 }
diff --git a/tests/TransformStreamTest.php b/tests/TransformStreamTest.php
index 87c25d2..1ad3fa0 100644
--- a/tests/TransformStreamTest.php
+++ b/tests/TransformStreamTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\TransformStream;
 use React\Stream\ThroughStream;
 
diff --git a/tests/ZlibCompressorTest.php b/tests/ZlibCompressorTest.php
index 2272438..6be5933 100644
--- a/tests/ZlibCompressorTest.php
+++ b/tests/ZlibCompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Compressor;
 
 class ZlibCompressorTest extends TestCase
diff --git a/tests/ZlibDecompressorTest.php b/tests/ZlibDecompressorTest.php
index 7d2c9dc..e30dcea 100644
--- a/tests/ZlibDecompressorTest.php
+++ b/tests/ZlibDecompressorTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Clue\Tests\React\Zlib;
+
 use Clue\React\Zlib\Decompressor;
 
 class ZlibDecompressorTest extends TestCase