diff --git a/src/Emitter/SapiStreamEmitter.php b/src/Emitter/SapiStreamEmitter.php
index 445560d..393ea93 100644
--- a/src/Emitter/SapiStreamEmitter.php
+++ b/src/Emitter/SapiStreamEmitter.php
@@ -19,7 +19,7 @@ class SapiStreamEmitter implements EmitterInterface
     use SapiEmitterTrait;
 
     /** @var int Maximum output buffering size for each iteration. */
-    private $maxBufferLength;
+    private int $maxBufferLength;
 
     public function __construct(int $maxBufferLength = 8192)
     {
diff --git a/src/RequestHandlerRunner.php b/src/RequestHandlerRunner.php
index f177b86..c628639 100644
--- a/src/RequestHandlerRunner.php
+++ b/src/RequestHandlerRunner.php
@@ -4,6 +4,7 @@
 
 namespace Laminas\HttpHandlerRunner;
 
+use Laminas\HttpHandlerRunner\Emitter\EmitterInterface;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\RequestHandlerInterface;
@@ -22,15 +23,12 @@
  */
 final class RequestHandlerRunner implements RequestHandlerRunnerInterface
 {
-    /** @var Emitter\EmitterInterface */
-    private $emitter;
+    private EmitterInterface $emitter;
 
     /**
      * A request handler to run as the application.
-     *
-     * @var RequestHandlerInterface
      */
-    private $handler;
+    private RequestHandlerInterface $handler;
 
     /**
      * A factory capable of generating an error response in the scenario that
@@ -58,7 +56,7 @@ final class RequestHandlerRunner implements RequestHandlerRunnerInterface
      */
     public function __construct(
         RequestHandlerInterface $handler,
-        Emitter\EmitterInterface $emitter,
+        EmitterInterface $emitter,
         callable $serverRequestFactory,
         callable $serverRequestErrorResponseGenerator
     ) {
diff --git a/test/ConfigProviderTest.php b/test/ConfigProviderTest.php
index 341714f..823e523 100644
--- a/test/ConfigProviderTest.php
+++ b/test/ConfigProviderTest.php
@@ -9,8 +9,7 @@
 
 class ConfigProviderTest extends TestCase
 {
-    /** @var ConfigProvider */
-    private $provider;
+    private ConfigProvider $provider;
 
     public function setUp(): void
     {
diff --git a/test/Emitter/EmitterStackTest.php b/test/Emitter/EmitterStackTest.php
index 6dd021d..525ddc0 100644
--- a/test/Emitter/EmitterStackTest.php
+++ b/test/Emitter/EmitterStackTest.php
@@ -13,8 +13,7 @@
 
 class EmitterStackTest extends TestCase
 {
-    /** @var EmitterStack */
-    private $emitter;
+    private EmitterStack $emitter;
 
     public function setUp(): void
     {
diff --git a/test/Emitter/SapiStreamEmitterTest.php b/test/Emitter/SapiStreamEmitterTest.php
index 3dd7a55..0726488 100644
--- a/test/Emitter/SapiStreamEmitterTest.php
+++ b/test/Emitter/SapiStreamEmitterTest.php
@@ -43,9 +43,7 @@ public function setUp(): void
 
     public function testEmitCallbackStreamResponse(): void
     {
-        $stream   = new CallbackStream(function () {
-            return 'it works';
-        });
+        $stream   = new CallbackStream(static fn(): string => 'it works');
         $response = (new Response())
             ->withStatus(200)
             ->withBody($stream);
@@ -124,7 +122,7 @@ public function testEmitStreamResponse(bool $seekable, bool $readable, string $c
             $contents,
             strlen($contents),
             $startPosition,
-            function (int $bufferLength) use (&$peakBufferLength): void {
+            static function (int $bufferLength) use (&$peakBufferLength): void {
                 self::assertIsInt($peakBufferLength);
                 if ($bufferLength > $peakBufferLength) {
                     $peakBufferLength = $bufferLength;
@@ -420,7 +418,7 @@ public function testEmitMemoryUsage(
             $peakMemoryUsage = (int) max($peakMemoryUsage, memory_get_usage());
         };
 
-        $contentsCallback = function (int $position, ?int $length = null) use (&$sizeBytes): string {
+        $contentsCallback = static function (int $position, ?int $length = null) use (&$sizeBytes): string {
             self::assertIsInt($sizeBytes);
             if (! $length) {
                 $length = $sizeBytes - $position;
@@ -429,7 +427,7 @@ public function testEmitMemoryUsage(
             return str_repeat('0', $length);
         };
 
-        $trackPeakBufferLength = function (int $bufferLength) use (&$peakBufferLength): void {
+        $trackPeakBufferLength = static function (int $bufferLength) use (&$peakBufferLength): void {
             if ($bufferLength > $peakBufferLength) {
                 $peakBufferLength = $bufferLength;
             }
@@ -476,7 +474,7 @@ public function testEmitMemoryUsage(
         }
 
         ob_start(
-            function () use (&$closureTrackMemoryUsage) {
+            static function () use (&$closureTrackMemoryUsage): string {
                 self::assertIsCallable($closureTrackMemoryUsage);
                 $closureTrackMemoryUsage();
                 return '';
@@ -610,9 +608,7 @@ public function testContentRange(string $header, string $body, string $expected)
 
     public function testContentRangeUnseekableBody(): void
     {
-        $body     = new CallbackStream(function () {
-            return 'Hello world';
-        });
+        $body     = new CallbackStream(static fn(): string => 'Hello world');
         $response = (new Response())
             ->withBody($body)
             ->withHeader('Content-Range', 'bytes 3-6/*');
diff --git a/test/RequestHandlerRunnerTest.php b/test/RequestHandlerRunnerTest.php
index 7b9cd9b..f3a3cb7 100644
--- a/test/RequestHandlerRunnerTest.php
+++ b/test/RequestHandlerRunnerTest.php
@@ -19,13 +19,18 @@ class RequestHandlerRunnerTest extends TestCase
     public function testUsesErrorResponseGeneratorToGenerateResponseWhenRequestFactoryRaisesException(): void
     {
         $exception            = new Exception();
-        $serverRequestFactory = function () use ($exception): ServerRequestInterface {
+        $serverRequestFactory = static function () use ($exception): ServerRequestInterface {
             throw $exception;
         };
 
         $response = $this->createMock(ResponseInterface::class);
 
-        $errorResponseGenerator = function (Throwable $passedThrowable) use ($exception, $response): ResponseInterface {
+        $errorResponseGenerator = static function (
+            Throwable $passedThrowable
+        ) use (
+            $exception,
+            $response
+        ): ResponseInterface {
             Assert::assertSame($exception, $passedThrowable);
             return $response;
         };
@@ -50,11 +55,9 @@ public function testRunPassesRequestGeneratedByRequestFactoryToHandleWhenNoReque
     {
         $request = $this->createMock(ServerRequestInterface::class);
 
-        $serverRequestFactory = function () use ($request): ServerRequestInterface {
-            return $request;
-        };
+        $serverRequestFactory = static fn(): ServerRequestInterface => $request;
 
-        $errorResponseGenerator = function (): ResponseInterface {
+        $errorResponseGenerator = static function (): ResponseInterface {
             self::fail('Should never hit error response generator');
         };
 
diff --git a/test/TestAsset/HeaderStack.php b/test/TestAsset/HeaderStack.php
index 44d0a68..23bd496 100644
--- a/test/TestAsset/HeaderStack.php
+++ b/test/TestAsset/HeaderStack.php
@@ -15,7 +15,7 @@ class HeaderStack
      * @var string[][]
      * @psalm-var list<HeaderType>
      */
-    private static $data = [];
+    private static array $data = [];
 
     /**
      * Reset state
diff --git a/test/TestAsset/HeadersSent.php b/test/TestAsset/HeadersSent.php
index a99b9f7..59b8054 100644
--- a/test/TestAsset/HeadersSent.php
+++ b/test/TestAsset/HeadersSent.php
@@ -9,8 +9,7 @@
 
 final class HeadersSent
 {
-    /** @var bool */
-    private static $headerSent = false;
+    private static bool $headerSent = false;
     /** @var null|string */
     public static $filename;
     /** @var null|int */
diff --git a/test/TestAsset/MockStreamHelper.php b/test/TestAsset/MockStreamHelper.php
index c122b79..60d7fd6 100644
--- a/test/TestAsset/MockStreamHelper.php
+++ b/test/TestAsset/MockStreamHelper.php
@@ -15,14 +15,11 @@ class MockStreamHelper
     /** @var string|callable(int,?int=null):string */
     private $contents;
 
-    /** @var int */
-    private $position;
+    private int $position;
 
-    /** @var int */
-    private $size;
+    private int $size;
 
-    /** @var int */
-    private $startPosition;
+    private int $startPosition;
 
     /** @var null|callable */
     private $trackPeakBufferLength;