diff --git a/.github/workflows/functionaltests.yml b/.github/workflows/functionaltests.yml
index 776610a..9937562 100644
--- a/.github/workflows/functionaltests.yml
+++ b/.github/workflows/functionaltests.yml
@@ -10,12 +10,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: [ 7.4 ]
-        flow-version: [ 5.3 ]
+        php-version: [ 8.1, 8.2 ]
+        flow-version: [ 8.3 ]
         mysql-version: [5.7]
 
-        exclude: []
-
     env:
       APP_ENV: true
       FLOW_CONTEXT: Testing/Functional
diff --git a/.github/workflows/unittests.yml b/.github/workflows/unittests.yml
index 2bbc35f..ff99b5d 100644
--- a/.github/workflows/unittests.yml
+++ b/.github/workflows/unittests.yml
@@ -10,10 +10,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: [ 7.4 ]
-        flow-version: [ 5.3 ]
-
-        exclude: []
+        php-version: [ 8.1, 8.2 ]
+        flow-version: [ 8.3 ]
 
     env:
       FLOW_CONTEXT: Testing/Unit
diff --git a/Classes/Domain/Model/ResourceProxy.php b/Classes/Domain/Model/ResourceProxy.php
index dcc58ee..e920d7f 100644
--- a/Classes/Domain/Model/ResourceProxy.php
+++ b/Classes/Domain/Model/ResourceProxy.php
@@ -10,8 +10,8 @@
  * source code.
  */
 
+use GuzzleHttp\Psr7\Uri;
 use Neos\Flow\Annotations as Flow;
-use Neos\Flow\Http\Uri;
 use Netlogix\JsonApiOrg\Consumer\Service\ConsumerBackendInterface;
 
 class ResourceProxy implements \ArrayAccess
diff --git a/Classes/Domain/Model/ResourceProxyIterator.php b/Classes/Domain/Model/ResourceProxyIterator.php
index 58a1d8d..0ee3a25 100644
--- a/Classes/Domain/Model/ResourceProxyIterator.php
+++ b/Classes/Domain/Model/ResourceProxyIterator.php
@@ -5,8 +5,8 @@
 
 use Neos\Cache\Frontend\VariableFrontend;
 use Neos\Flow\Cache\CacheManager;
-use Neos\Flow\Http\Uri;
 use Neos\Flow\Utility\Now;
+use Psr\Http\Message\UriInterface;
 
 class ResourceProxyIterator implements \IteratorAggregate, \Countable
 {
@@ -45,7 +45,7 @@ protected function __construct(string $uri = '')
         $this->uri = $uri;
     }
 
-    public static function fromUri(Uri $uri): self
+    public static function fromUri(UriInterface $uri): self
     {
         return new static((string)$uri);
     }
diff --git a/Classes/Domain/Model/Type.php b/Classes/Domain/Model/Type.php
index a8ef1b7..04d0283 100644
--- a/Classes/Domain/Model/Type.php
+++ b/Classes/Domain/Model/Type.php
@@ -11,8 +11,8 @@
  */
 
 use Neos\Flow\Annotations as Flow;
-use Neos\Flow\Http\Uri;
 use Neos\Flow\ObjectManagement\ObjectManagerInterface;
+use Psr\Http\Message\UriInterface;
 
 class Type
 {
@@ -57,7 +57,7 @@ class Type
     protected $properties = [];
 
     /**
-     * @var Uri
+     * @var UriInterface
      */
     protected $uri;
 
@@ -76,14 +76,14 @@ class Type
      * @param string $typeName
      * @param string $resourceClassName
      * @param array $properties
-     * @param Uri $uri
+     * @param UriInterface $uri
      * @param array $defaultIncludes
      */
     public function __construct(
         $typeName,
         $resourceClassName = ResourceProxy::class,
         array $properties = [],
-        Uri $uri = null,
+        UriInterface $uri = null,
         array $defaultIncludes = []
     ) {
         $this->typeName = (string)$typeName;
@@ -95,19 +95,12 @@ public function __construct(
         $this->defaultIncludes = $defaultIncludes;
     }
 
-    /**
-     * @return Uri
-     */
-    public function getUri()
+    public function getUri(): UriInterface
     {
         return $this->uri;
     }
 
-    /**
-     * @param Uri $uri
-     * @return void
-     */
-    public function setUri(Uri $uri)
+    public function setUri(UriInterface $uri): void
     {
         $this->uri = $uri;
     }
diff --git a/Classes/Guzzle/Middleware/EndpointCacheMiddleware.php b/Classes/Guzzle/Middleware/EndpointCacheMiddleware.php
index 4b7ade6..9ae7ca0 100644
--- a/Classes/Guzzle/Middleware/EndpointCacheMiddleware.php
+++ b/Classes/Guzzle/Middleware/EndpointCacheMiddleware.php
@@ -31,7 +31,7 @@ public function __invoke(callable $handler)
                 return $handler($request, $options);
             }
 
-            $requestPath = $request->getUri()->getPath() ?? '';
+            $requestPath = $request->getUri()->getPath() ?: '';
             if (!self::str_ends_with(rtrim($requestPath, '/'), '/.well-known/endpoint-discovery')) {
                 return $handler($request, $options);
             }
diff --git a/Classes/Service/ConsumerBackend.php b/Classes/Service/ConsumerBackend.php
index cb3adfc..c411386 100644
--- a/Classes/Service/ConsumerBackend.php
+++ b/Classes/Service/ConsumerBackend.php
@@ -11,17 +11,18 @@
  */
 
 use GuzzleHttp\Client;
+use GuzzleHttp\Psr7\Uri;
 use Neos\Cache\Exception\InvalidDataException;
 use Neos\Cache\Frontend\StringFrontend;
 use Neos\Flow\Annotations as Flow;
 use Neos\Flow\Http\Helper\UriHelper;
-use Neos\Flow\Http\Uri;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\Arguments\PageInterface;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\Arguments\SortInterface;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\ResourceProxy;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\ResourceProxyIterator;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\Type;
 use Netlogix\JsonApiOrg\Consumer\Guzzle\ClientProvider;
+use Psr\Http\Message\UriInterface;
 
 /**
  * @Flow\Scope("singleton")
@@ -83,11 +84,11 @@ public function getType($typeName)
     }
 
     /**
-     * @param Uri $endpointDiscovery
+     * @param UriInterface $endpointDiscovery
      * @throws InvalidDataException
      * @throws \Neos\Cache\Exception
      */
-    public function registerEndpointsByEndpointDiscovery(Uri $endpointDiscovery)
+    public function registerEndpointsByEndpointDiscovery(UriInterface $endpointDiscovery)
     {
         $result = $this->requestJson($endpointDiscovery);
         foreach ($result['links'] as $link) {
@@ -180,12 +181,12 @@ public function getQueryUriForFindByTypeAndFilter(
     }
 
     /**
-     * @param Uri $queryUri
+     * @param UriInterface $queryUri
      * @return ResourceProxyIterator
      * @throws InvalidDataException
      * @throws \Neos\Cache\Exception
      */
-    public function fetchFromUri(Uri $queryUri)
+    public function fetchFromUri(UriInterface $queryUri)
     {
         $resourceProxy = ResourceProxyIterator::fromUri($queryUri);
         $resourceProxy = $resourceProxy->loadFromCache();
diff --git a/Classes/Service/ConsumerBackendInterface.php b/Classes/Service/ConsumerBackendInterface.php
index 98a21e7..57a7c40 100644
--- a/Classes/Service/ConsumerBackendInterface.php
+++ b/Classes/Service/ConsumerBackendInterface.php
@@ -10,12 +10,12 @@
  * source code.
  */
 
-use Neos\Flow\Http\Uri;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\Arguments\PageInterface;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\Arguments\SortInterface;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\ResourceProxy;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\ResourceProxyIterator;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model\Type;
+use Psr\Http\Message\UriInterface;
 
 interface ConsumerBackendInterface
 {
@@ -31,9 +31,9 @@ public function addType(Type $type);
     public function getType($typeName);
 
     /**
-     * @param Uri $endpointDiscovery
+     * @param UriInterface $endpointDiscovery
      */
-    public function registerEndpointsByEndpointDiscovery(Uri $endpointDiscovery);
+    public function registerEndpointsByEndpointDiscovery(UriInterface $endpointDiscovery);
 
     /**
      * @param string $type
@@ -46,10 +46,10 @@ public function registerEndpointsByEndpointDiscovery(Uri $endpointDiscovery);
     public function findByTypeAndFilter($type, $filter = [], $include = [], PageInterface $page = null, SortInterface $sort = null);
 
     /**
-     * @param Uri $queryUri
+     * @param UriInterface $queryUri
      * @return ResourceProxyIterator
      */
-    public function fetchFromUri(Uri $queryUri);
+    public function fetchFromUri(UriInterface $queryUri);
 
     /**
      * @param mixed $type
diff --git a/Tests/Common/Guzzle/NoResponseQueued.php b/Tests/Common/Guzzle/NoResponseQueued.php
new file mode 100644
index 0000000..3da333f
--- /dev/null
+++ b/Tests/Common/Guzzle/NoResponseQueued.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Netlogix\JsonApiOrg\Consumer\Tests\Common\Guzzle;
+
+class NoResponseQueued extends \RuntimeException
+{
+}
\ No newline at end of file
diff --git a/Tests/Common/Guzzle/TestingClientProvider.php b/Tests/Common/Guzzle/TestingClientProvider.php
index 4238da7..f67756f 100644
--- a/Tests/Common/Guzzle/TestingClientProvider.php
+++ b/Tests/Common/Guzzle/TestingClientProvider.php
@@ -57,7 +57,7 @@ public function createClient(): Client
             }
 
             if (strpos($uri, 'resource://') === 0
-                || strpos($uri, 'data://') === 0) {
+                || strpos($uri, 'data:') === 0) {
                 $uri = (string) $requestUri
                     ->withQuery('')
                     ->withFragment('');
@@ -72,7 +72,7 @@ public function createClient(): Client
                 );
             }
 
-            throw new \RuntimeException(sprintf('No Response queued for URI "%s"', $uri), 1624304664);
+            throw new NoResponseQueued(sprintf('No Response queued for URI "%s"', $uri), 1624304664);
         };
 
         $handlerStack = HandlerStack::create($requestHandler);
diff --git a/Tests/Functional/CachingTest.php b/Tests/Functional/CachingTest.php
index 9db67f2..4d31035 100644
--- a/Tests/Functional/CachingTest.php
+++ b/Tests/Functional/CachingTest.php
@@ -3,10 +3,13 @@
 
 namespace Netlogix\JsonApiOrg\Consumer\Tests\Functional;
 
+use GuzzleHttp\Psr7\Uri;
+use Neos\Cache\Backend\FileBackendEntryDto;
 use Neos\Cache\Backend\WithSetupInterface;
 use Neos\Cache\Frontend\FrontendInterface;
 use Neos\Flow\Cache\CacheManager;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model as JsonApi;
+use Netlogix\JsonApiOrg\Consumer\Tests\Common\Guzzle\NoResponseQueued;
 
 class CachingTest extends FunctionalTestCase
 {
@@ -22,6 +25,7 @@ public function setUp(): void
         if ($cache->getBackend() instanceof WithSetupInterface) {
             $cache->getBackend()->setup();
         }
+        $cache->flush();
     }
 
     /**
@@ -30,7 +34,7 @@ public function setUp(): void
      */
     public function JSON_data_can_be_saved_to_cache(array $jsonApiFixture)
     {
-        $uri = $this->asDataUri([]);
+        $uri = new Uri('https://some-url.example/foo');
 
         JsonApi\ResourceProxyIterator::fromUri($uri)
             ->withJsonResult($jsonApiFixture)
@@ -50,19 +54,30 @@ public function JSON_data_can_be_saved_to_cache(array $jsonApiFixture)
      */
     public function Cached_data_respects_cache_lifetime(array $jsonApiFixture)
     {
-        $uri = $this->asDataUri([]);
+        $uri = new Uri('https://some-url.example/foo');
 
         JsonApi\ResourceProxyIterator::fromUri($uri)
             ->withJsonResult($jsonApiFixture)
             ->saveToCache(1);
 
+        /**
+         * @see FileBackendEntryDto::isExpired()
+         */
+        $previousTime = $_SERVER['REQUEST_TIME'];
+        $_SERVER['REQUEST_TIME'] = time() + 2;
         sleep(2);
 
-        $result = $this->consumerBackend
-            ->fetchFromUri($uri)
-            ->getArrayCopy();
+        self::expectException(NoResponseQueued::class);
 
-        $this->assertCount(0, $result);
+        try {
+            $this->consumerBackend
+                ->fetchFromUri($uri)
+                ->getArrayCopy();
+        } catch (\Throwable $t) {
+            throw $t;
+        } finally {
+            $_SERVER['REQUEST_TIME'] = $previousTime;
+        }
     }
 
     /**
@@ -71,7 +86,7 @@ public function Cached_data_respects_cache_lifetime(array $jsonApiFixture)
      */
     public function Cached_data_will_not_be_written_to_cache_again_with_same_lifetime_and_tags(array $jsonApiFixture)
     {
-        $uri = $this->asDataUri([]);
+        $uri = new Uri('https://some-url.example/foo');
         $tags = ['foo', 'bar', 'baz'];
 
         JsonApi\ResourceProxyIterator::fromUri($uri)
@@ -101,7 +116,7 @@ public function Cached_data_will_not_be_written_to_cache_again_with_same_lifetim
      */
     public function Cached_data_will_not_be_written_to_cache_again_with_same_lifetime_and_differently_ordered_tags(array $jsonApiFixture)
     {
-        $uri = $this->asDataUri([]);
+        $uri = new Uri('https://some-url.example/foo');
         $tags = ['foo', 'bar', 'baz'];
 
         JsonApi\ResourceProxyIterator::fromUri($uri)
@@ -131,7 +146,7 @@ public function Cached_data_will_not_be_written_to_cache_again_with_same_lifetim
      */
     public function Cached_data_will_be_written_to_cache_again_if_lifetime_differs(array $jsonApiFixture)
     {
-        $uri = $this->asDataUri([]);
+        $uri = new Uri('https://some-url.example/foo');
         $tags = ['foo', 'bar', 'baz'];
 
         JsonApi\ResourceProxyIterator::fromUri($uri)
@@ -161,7 +176,7 @@ public function Cached_data_will_be_written_to_cache_again_if_lifetime_differs(a
      */
     public function Cached_data_will_be_written_to_cache_again_if_tags_differs(array $jsonApiFixture)
     {
-        $uri = $this->asDataUri([]);
+        $uri = new Uri('https://some-url.example/foo');
         $tags = ['foo', 'bar', 'baz'];
 
         JsonApi\ResourceProxyIterator::fromUri($uri)
diff --git a/Tests/Functional/FunctionalTestCase.php b/Tests/Functional/FunctionalTestCase.php
index 42fe3fc..a586119 100644
--- a/Tests/Functional/FunctionalTestCase.php
+++ b/Tests/Functional/FunctionalTestCase.php
@@ -3,10 +3,11 @@
 
 namespace Netlogix\JsonApiOrg\Consumer\Tests\Functional;
 
-use Neos\Flow\Http\Uri;
+use GuzzleHttp\Psr7\Uri;
 use Neos\Flow\Tests\FunctionalTestCase as BaseTestCase;
 use Netlogix\JsonApiOrg\Consumer\Domain\Model as JsonApi;
 use Netlogix\JsonApiOrg\Consumer\Service\ConsumerBackend;
+use Psr\Http\Message\UriInterface;
 
 class FunctionalTestCase extends BaseTestCase
 {
@@ -49,13 +50,13 @@ public function createEmptyResource(): JsonApi\ResourceProxy
         $this->type->__consumerBackend = $this->consumerBackend;
     }
 
-    public function asDataUri(array $fixture): Uri
+    public function asDataUri(array $fixture): UriInterface
     {
         $dataUri = 'data:application/json;base64,' . base64_encode(json_encode($fixture));
         return new Uri($dataUri);
     }
 
-    public function provideJsonResponse()
+    public static function provideJsonResponse()
     {
         $entity = [
             'id' => 0,
diff --git a/Tests/Unit/Guzzle/Middleware/ClosureLike.php b/Tests/Unit/Guzzle/Middleware/ClosureLike.php
new file mode 100644
index 0000000..40740e7
--- /dev/null
+++ b/Tests/Unit/Guzzle/Middleware/ClosureLike.php
@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Netlogix\JsonApiOrg\Consumer\Tests\Unit\Guzzle\Middleware;
+
+use Psr\Http\Message\RequestInterface;
+
+interface ClosureLike
+{
+    public function __invoke(RequestInterface $request, array $options);
+}
\ No newline at end of file
diff --git a/Tests/Unit/Guzzle/Middleware/EndpointCacheMiddlewareTest.php b/Tests/Unit/Guzzle/Middleware/EndpointCacheMiddlewareTest.php
index ec887c3..477ab89 100644
--- a/Tests/Unit/Guzzle/Middleware/EndpointCacheMiddlewareTest.php
+++ b/Tests/Unit/Guzzle/Middleware/EndpointCacheMiddlewareTest.php
@@ -8,6 +8,7 @@
 use GuzzleHttp\Psr7\Request;
 use GuzzleHttp\Psr7\Response;
 use GuzzleHttp\Promise\PromiseInterface;
+use GuzzleHttp\Psr7\Uri;
 use Neos\Cache\Frontend\VariableFrontend;
 use Neos\Flow\Tests\UnitTestCase;
 use Netlogix\JsonApiOrg\Consumer\Guzzle\Middleware\EndpointCacheMiddleware;
@@ -42,7 +43,7 @@ public function Cache_only_safe_methods()
         $request = new Request('POST', '/uri');
         $options = [];
 
-        $mock = $this->createPartialMock(\stdClass::class, ['__invoke']);
+        $mock = $this->getMockBuilder(ClosureLike::class)->getMock();
         $mock->expects($this->once())
             ->method('__invoke')
             ->with($request, $options);
@@ -59,7 +60,7 @@ public function Cache_only_endpoint_discovery()
         $request = new Request('GET', '/uri');
         $options = [];
 
-        $mock = $this->createPartialMock(\stdClass::class, ['__invoke']);
+        $mock = $this->getMockBuilder(ClosureLike::class)->getMock();
         $mock->expects($this->once())
             ->method('__invoke')
             ->with($request, $options);
@@ -73,14 +74,14 @@ public function Cache_only_endpoint_discovery()
      */
     public function Empty_paths_dont_cause_exception()
     {
-        $uri = new \Neos\Flow\Http\Uri('https://foo');
+        $uri = new Uri('https://foo');
         $request = new Request('GET', $uri);
 
-        $this->assertNull($uri->getPath());
+        $this->assertEmpty($uri->getPath());
 
         $options = [];
 
-        $mock = $this->createPartialMock(\stdClass::class, ['__invoke']);
+        $mock = $this->getMockBuilder(ClosureLike::class)->getMock();
         $mock->expects($this->once())
             ->method('__invoke')
             ->with($request, $options);
@@ -102,11 +103,11 @@ public function Endpoint_discovery_result_is_written_to_cache()
         $promise
             ->expects($this->once())
             ->method('then')
-            ->will($this->returnCallback(function (\Closure $callback) use($response) {
-                return $callback($response);
+            ->will($this->returnCallback(function (\Closure $callback) use ($response) {
+                return new FulfilledPromise($callback($response));
             }));
 
-        $mock = $this->createPartialMock(\stdClass::class, ['__invoke']);
+        $mock = $this->getMockBuilder(ClosureLike::class)->getMock();
         $mock->expects($this->once())
             ->method('__invoke')
             ->with($request, $options)
@@ -131,7 +132,7 @@ public function Endpoint_discovery_result_is_read_from_cache()
         $response = $this->getResponse();
         $options = [];
 
-        $mock = $this->createPartialMock(\stdClass::class, ['__invoke']);
+        $mock = $this->getMockBuilder(ClosureLike::class)->getMock();
         $mock->expects($this->never())
             ->method('__invoke');
 
@@ -165,11 +166,9 @@ public function Only_200_status_code_is_cached()
         $promise
             ->expects($this->once())
             ->method('then')
-            ->will($this->returnCallback(function (\Closure $callback) use($response) {
-                return $callback($response);
-            }));
+            ->willReturn(new FulfilledPromise($response));
 
-        $mock = $this->createPartialMock(\stdClass::class, ['__invoke']);
+        $mock = $this->getMockBuilder(ClosureLike::class)->getMock();
         $mock->expects($this->once())
             ->method('__invoke')
             ->with($request, $options)
diff --git a/composer.json b/composer.json
index 525e856..d2228d8 100644
--- a/composer.json
+++ b/composer.json
@@ -7,11 +7,11 @@
         "MIT"
     ],
     "require": {
-        "php": "^7.4 || ^8.0 || ^8.1",
+        "php": "^8.1",
         "ext-json": "*",
         "guzzlehttp/guzzle": "^6.5 || ^7.0",
-        "guzzlehttp/promises": "^1.4",
-        "neos/flow": "^5.3 || ^6.3 || ^7.3"
+        "guzzlehttp/promises": "^1.4 || ^2.0",
+        "neos/flow": "^8.3"
     },
     "autoload": {
         "psr-4": {
@@ -28,7 +28,6 @@
             "neos/composer-plugin": false
         }
     },
-
     "extra": {
         "neos": {
             "package-key": "Netlogix.JsonApiOrg.Consumer"