diff --git a/composer.json b/composer.json
index e0315eb..9630942 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
         "ringcentral/psr7": "^1.2"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.0 || ^5.0 || ^4.8",
+        "phpunit/phpunit": "^9.0 || ^7.0 || ^5.0 || ^4.8",
         "react/event-loop": "^1.0 || ^0.5 || ^0.4 || ^0.3",
         "clue/block-react": "^1.1"
     }
diff --git a/tests/AbstractTestCase.php b/tests/AbstractTestCase.php
index b145410..f6102fd 100644
--- a/tests/AbstractTestCase.php
+++ b/tests/AbstractTestCase.php
@@ -54,5 +54,19 @@ protected function createCallableMock()
     {
         return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
     }
+
+    public function setExpectedException($exception, $message = '', $code = 0)
+    {
+        if (method_exists($this, 'expectException')) {
+            $this->expectException($exception);
+            if ($message !== '') {
+                $this->expectExceptionMessage($message);
+            }
+            $this->expectExceptionCode($code);
+        } else {
+            parent::setExpectedException($exception, $message, $code);
+        }
+    }
+
 }
 
diff --git a/tests/FunctionalTest.php b/tests/FunctionalTest.php
index f0b0a88..4cf1101 100644
--- a/tests/FunctionalTest.php
+++ b/tests/FunctionalTest.php
@@ -16,7 +16,10 @@ class FunctionalTest extends AbstractTestCase
     private $tcpConnector;
     private $dnsConnector;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpConnector()
     {
         $this->loop = Factory::create();
 
diff --git a/tests/ProxyConnectorTest.php b/tests/ProxyConnectorTest.php
index f6f6276..1ae2f09 100644
--- a/tests/ProxyConnectorTest.php
+++ b/tests/ProxyConnectorTest.php
@@ -11,32 +11,29 @@ class ProxyConnectorTest extends AbstractTestCase
 {
     private $connector;
 
-    public function setUp()
+    /**
+     * @before
+     */
+    public function setUpMock()
     {
         $this->connector = $this->getMockBuilder('React\Socket\ConnectorInterface')->getMock();
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testInvalidProxy()
     {
+        $this->setExpectedException('InvalidArgumentException');
         new ProxyConnector('///', $this->connector);
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testInvalidProxyScheme()
     {
+        $this->setExpectedException('InvalidArgumentException');
         new ProxyConnector('ftp://example.com', $this->connector);
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testInvalidHttpsUnixScheme()
     {
+        $this->setExpectedException('InvalidArgumentException');
         new ProxyConnector('https+unix:///tmp/proxy.sock', $this->connector);
     }