diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index bfdeecf6..19a4b901 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -4,8 +4,9 @@
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
          xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
          bootstrap="vendor/autoload.php"
+         cacheResult="false"
          colors="true"
-         cacheResult="false">
+         convertDeprecationsToExceptions="true">
     <testsuites>
         <testsuite name="React test suite">
             <directory>./tests/</directory>
diff --git a/tests/AbstractLoopTest.php b/tests/AbstractLoopTest.php
index 61790882..5b4da29e 100644
--- a/tests/AbstractLoopTest.php
+++ b/tests/AbstractLoopTest.php
@@ -12,8 +12,12 @@ abstract class AbstractLoopTest extends TestCase
      */
     protected $loop;
 
+    /** @var float */
     private $tickTimeout;
 
+    /** @var ?string */
+    private $received;
+
     const PHP_DEFAULT_CHUNK_SIZE = 8192;
 
     /**
diff --git a/tests/ExtEventLoopTest.php b/tests/ExtEventLoopTest.php
index 2f88d184..af4caa13 100644
--- a/tests/ExtEventLoopTest.php
+++ b/tests/ExtEventLoopTest.php
@@ -6,6 +6,9 @@
 
 class ExtEventLoopTest extends AbstractLoopTest
 {
+    /** @var ?string */
+    private $fifoPath;
+
     public function createLoop($readStreamCompatible = false)
     {
         if ('Linux' === PHP_OS && !extension_loaded('posix')) {
@@ -19,12 +22,23 @@ public function createLoop($readStreamCompatible = false)
         return new ExtEventLoop();
     }
 
+    /**
+     * @after
+     */
+    public function tearDownFile()
+    {
+        if ($this->fifoPath !== null && file_exists($this->fifoPath)) {
+            unlink($this->fifoPath);
+        }
+    }
+
     public function createStream()
     {
         // Use a FIFO on linux to get around lack of support for disk-based file
         // descriptors when using the EPOLL back-end.
         if ('Linux' === PHP_OS) {
             $this->fifoPath = tempnam(sys_get_temp_dir(), 'react-');
+            assert(is_string($this->fifoPath));
 
             unlink($this->fifoPath);
 
diff --git a/tests/ExtLibeventLoopTest.php b/tests/ExtLibeventLoopTest.php
index 32a852b8..524e0548 100644
--- a/tests/ExtLibeventLoopTest.php
+++ b/tests/ExtLibeventLoopTest.php
@@ -6,6 +6,7 @@
 
 class ExtLibeventLoopTest extends AbstractLoopTest
 {
+    /** @var ?string */
     private $fifoPath;
 
     public function createLoop()
@@ -26,7 +27,7 @@ public function createLoop()
      */
     public function tearDownFile()
     {
-        if (file_exists($this->fifoPath)) {
+        if ($this->fifoPath !== null && file_exists($this->fifoPath)) {
             unlink($this->fifoPath);
         }
     }
@@ -38,6 +39,7 @@ public function createStream()
         }
 
         $this->fifoPath = tempnam(sys_get_temp_dir(), 'react-');
+        assert(is_string($this->fifoPath));
 
         unlink($this->fifoPath);
 
diff --git a/tests/bin/01-ticks-loop-class.php b/tests/bin/01-ticks-loop-class.php
index f4fcedf1..5d499f92 100644
--- a/tests/bin/01-ticks-loop-class.php
+++ b/tests/bin/01-ticks-loop-class.php
@@ -2,7 +2,8 @@
 
 use React\EventLoop\Loop;
 
-require __DIR__ . '/../../vendor/autoload.php';
+// autoload for local project development or project installed as dependency for reactphp/reactphp
+(@include __DIR__ . '/../../vendor/autoload.php') || require __DIR__ . '/../../../../autoload.php';
 
 Loop::futureTick(function () {
     echo 'b';
diff --git a/tests/bin/02-ticks-loop-instance.php b/tests/bin/02-ticks-loop-instance.php
index 57e58c92..5aeead84 100644
--- a/tests/bin/02-ticks-loop-instance.php
+++ b/tests/bin/02-ticks-loop-instance.php
@@ -2,7 +2,8 @@
 
 use React\EventLoop\Loop;
 
-require __DIR__ . '/../../vendor/autoload.php';
+// autoload for local project development or project installed as dependency for reactphp/reactphp
+(@include __DIR__ . '/../../vendor/autoload.php') || require __DIR__ . '/../../../../autoload.php';
 
 $loop = Loop::get();
 
diff --git a/tests/bin/03-ticks-loop-stop.php b/tests/bin/03-ticks-loop-stop.php
index d8b65946..87317563 100644
--- a/tests/bin/03-ticks-loop-stop.php
+++ b/tests/bin/03-ticks-loop-stop.php
@@ -2,7 +2,8 @@
 
 use React\EventLoop\Loop;
 
-require __DIR__ . '/../../vendor/autoload.php';
+// autoload for local project development or project installed as dependency for reactphp/reactphp
+(@include __DIR__ . '/../../vendor/autoload.php') || require __DIR__ . '/../../../../autoload.php';
 
 $loop = Loop::get();
 
diff --git a/tests/bin/11-uncaught.php b/tests/bin/11-uncaught.php
index 0655698b..c5bf8c70 100644
--- a/tests/bin/11-uncaught.php
+++ b/tests/bin/11-uncaught.php
@@ -2,7 +2,8 @@
 
 use React\EventLoop\Loop;
 
-require __DIR__ . '/../../vendor/autoload.php';
+// autoload for local project development or project installed as dependency for reactphp/reactphp
+(@include __DIR__ . '/../../vendor/autoload.php') || require __DIR__ . '/../../../../autoload.php';
 
 Loop::addTimer(10.0, function () {
     echo 'never';
diff --git a/tests/bin/12-undefined.php b/tests/bin/12-undefined.php
index 66d0d726..c45cc0f4 100644
--- a/tests/bin/12-undefined.php
+++ b/tests/bin/12-undefined.php
@@ -2,7 +2,8 @@
 
 use React\EventLoop\Loop;
 
-require __DIR__ . '/../../vendor/autoload.php';
+// autoload for local project development or project installed as dependency for reactphp/reactphp
+(@include __DIR__ . '/../../vendor/autoload.php') || require __DIR__ . '/../../../../autoload.php';
 
 Loop::get()->addTimer(10.0, function () {
     echo 'never';
diff --git a/tests/bin/21-stop.php b/tests/bin/21-stop.php
index 038d9223..182ee016 100644
--- a/tests/bin/21-stop.php
+++ b/tests/bin/21-stop.php
@@ -2,7 +2,8 @@
 
 use React\EventLoop\Loop;
 
-require __DIR__ . '/../../vendor/autoload.php';
+// autoload for local project development or project installed as dependency for reactphp/reactphp
+(@include __DIR__ . '/../../vendor/autoload.php') || require __DIR__ . '/../../../../autoload.php';
 
 Loop::addTimer(10.0, function () {
     echo 'never';
diff --git a/tests/bin/22-stop-uncaught.php b/tests/bin/22-stop-uncaught.php
index f0c0ff8d..5b6142ed 100644
--- a/tests/bin/22-stop-uncaught.php
+++ b/tests/bin/22-stop-uncaught.php
@@ -2,7 +2,8 @@
 
 use React\EventLoop\Loop;
 
-require __DIR__ . '/../../vendor/autoload.php';
+// autoload for local project development or project installed as dependency for reactphp/reactphp
+(@include __DIR__ . '/../../vendor/autoload.php') || require __DIR__ . '/../../../../autoload.php';
 
 Loop::addTimer(10.0, function () {
     echo 'never';