diff --git a/composer.json b/composer.json
index 50efb6d8..8c61e378 100644
--- a/composer.json
+++ b/composer.json
@@ -46,9 +46,9 @@
         "php-http/curl-client": "<2.0"
     },
     "require-dev": {
-        "guzzlehttp/psr7": "^1.0",
         "matthiasnoback/symfony-dependency-injection-test": "^4.0",
         "nyholm/nsa": "^1.1",
+        "nyholm/psr7": "^1.2.1",
         "php-http/cache-plugin": "^1.7",
         "php-http/guzzle6-adapter": "^1.1.1 || ^2.0.1",
         "php-http/mock-client": "^1.2",
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 424fac67..e200ad81 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -120,9 +120,16 @@ public function getConfigTreeBuilder()
                     ->info('Configure which service the main alias point to.')
                     ->children()
                         ->scalarNode('client')->defaultValue('httplug.client.default')->end()
+                        ->scalarNode('psr18_client')->defaultValue('httplug.psr18_client.default')->end()
                         ->scalarNode('message_factory')->defaultValue('httplug.message_factory.default')->end()
                         ->scalarNode('uri_factory')->defaultValue('httplug.uri_factory.default')->end()
                         ->scalarNode('stream_factory')->defaultValue('httplug.stream_factory.default')->end()
+                        ->scalarNode('psr17_request_factory')->defaultValue('httplug.psr17_request_factory.default')->end()
+                        ->scalarNode('psr17_response_factory')->defaultValue('httplug.psr17_response_factory.default')->end()
+                        ->scalarNode('psr17_stream_factory')->defaultValue('httplug.psr17_stream_factory.default')->end()
+                        ->scalarNode('psr17_uri_factory')->defaultValue('httplug.psr17_uri_factory.default')->end()
+                        ->scalarNode('psr17_uploaded_file_factory')->defaultValue('httplug.psr17_uploaded_file_factory.default')->end()
+                        ->scalarNode('psr17_server_request_factory')->defaultValue('httplug.psr17_server_request_factory.default')->end()
                     ->end()
                 ->end()
                 ->arrayNode('classes')
@@ -130,9 +137,16 @@ public function getConfigTreeBuilder()
                     ->info('Overwrite a service class instead of using the discovery mechanism.')
                     ->children()
                         ->scalarNode('client')->defaultNull()->end()
+                        ->scalarNode('psr18_client')->defaultNull()->end()
                         ->scalarNode('message_factory')->defaultNull()->end()
                         ->scalarNode('uri_factory')->defaultNull()->end()
                         ->scalarNode('stream_factory')->defaultNull()->end()
+                        ->scalarNode('psr17_request_factory')->defaultNull()->end()
+                        ->scalarNode('psr17_response_factory')->defaultNull()->end()
+                        ->scalarNode('psr17_stream_factory')->defaultNull()->end()
+                        ->scalarNode('psr17_uri_factory')->defaultNull()->end()
+                        ->scalarNode('psr17_uploaded_file_factory')->defaultNull()->end()
+                        ->scalarNode('psr17_server_request_factory')->defaultNull()->end()
                     ->end()
                 ->end()
                 ->arrayNode('profiling')
diff --git a/src/Resources/config/services.xml b/src/Resources/config/services.xml
index 194921b8..d97d1215 100644
--- a/src/Resources/config/services.xml
+++ b/src/Resources/config/services.xml
@@ -46,6 +46,31 @@
         </service>
         <service id="Http\Client\HttpClient" alias="httplug.client" public="false" />
 
+        <!-- Discovery for PSR-18 -->
+        <service id="httplug.psr18_client.default" class="Psr\Http\Client\ClientInterface">
+            <factory class="Http\Discovery\Psr18ClientDiscovery" method="find" />
+        </service>
+
+        <!-- Discovery for PSR-17 -->
+        <service id="httplug.psr17_request_factory.default" class="Psr\Http\Message\RequestFactoryInterface">
+            <factory class="Http\Discovery\Psr17FactoryDiscovery" method="findRequestFactory" />
+        </service>
+        <service id="httplug.psr17_response_factory.default" class="Psr\Http\Message\ResponseFactoryInterface">
+            <factory class="Http\Discovery\Psr17FactoryDiscovery" method="findResponseFactory" />
+        </service>
+        <service id="httplug.psr17_stream_factory.default" class="Psr\Http\Message\StreamFactoryInterface">
+            <factory class="Http\Discovery\Psr17FactoryDiscovery" method="findStreamFactory" />
+        </service>
+        <service id="httplug.psr17_uri_factory.default" class="Psr\Http\Message\UriFactoryInterface">
+            <factory class="Http\Discovery\Psr17FactoryDiscovery" method="findUrlFactory" />
+        </service>
+        <service id="httplug.psr17_uploaded_file_factory.default" class="Psr\Http\Message\UploadedFileFactoryInterface">
+            <factory class="Http\Discovery\Psr17FactoryDiscovery" method="findUploadedFileFactory" />
+        </service>
+        <service id="httplug.psr17_server_request_factory.default" class="Psr\Http\Message\ServerRequestFactoryInterface">
+            <factory class="Http\Discovery\Psr17FactoryDiscovery" method="findServerRequestFactory" />
+        </service>
+
         <!-- PluginClientFactory -->
         <service id="Http\Client\Common\PluginClientFactory" class="Http\Client\Common\PluginClientFactory" public="false" />
 
@@ -55,8 +80,8 @@
             <argument type="service" id="httplug.message_factory"/>
         </service>
         <service id="httplug.factory.curl" class="Http\HttplugBundle\ClientFactory\CurlFactory" public="false">
-            <argument type="service" id="httplug.message_factory"/>
-            <argument type="service" id="httplug.stream_factory"/>
+            <argument type="service" id="httplug.psr17_response_factory"/>
+            <argument type="service" id="httplug.psr17_stream_factory"/>
         </service>
         <service id="httplug.factory.guzzle5" class="Http\HttplugBundle\ClientFactory\Guzzle5Factory" public="false">
             <argument type="service" id="httplug.message_factory"/>
diff --git a/tests/Resources/Fixtures/config/full.php b/tests/Resources/Fixtures/config/full.php
index c12643fb..8168d405 100644
--- a/tests/Resources/Fixtures/config/full.php
+++ b/tests/Resources/Fixtures/config/full.php
@@ -13,6 +13,13 @@
         'message_factory' => 'Http\Message\MessageFactory\GuzzleMessageFactory',
         'uri_factory'     => 'Http\Message\UriFactory\GuzzleUriFactory',
         'stream_factory'  => 'Http\Message\StreamFactory\GuzzleStreamFactory',
+        'psr18_client'    => 'Http\Adapter\Guzzle6\Client',
+        'psr17_request_factory'        => 'Nyholm\Psr7\Factory\Psr17Factory',
+        'psr17_response_factory'       => 'Nyholm\Psr7\Factory\Psr17Factory',
+        'psr17_stream_factory'         => 'Nyholm\Psr7\Factory\Psr17Factory',
+        'psr17_uri_factory'            => 'Nyholm\Psr7\Factory\Psr17Factory',
+        'psr17_uploaded_file_factory'  => 'Nyholm\Psr7\Factory\Psr17Factory',
+        'psr17_server_request_factory' => 'Nyholm\Psr7\Factory\Psr17Factory',
     ],
     'clients' => [
         'test' => [
diff --git a/tests/Resources/Fixtures/config/full.xml b/tests/Resources/Fixtures/config/full.xml
index 65fe8dd1..9405491e 100644
--- a/tests/Resources/Fixtures/config/full.xml
+++ b/tests/Resources/Fixtures/config/full.xml
@@ -14,6 +14,13 @@
             <message-factory>Http\Message\MessageFactory\GuzzleMessageFactory</message-factory>
             <uri-factory>Http\Message\UriFactory\GuzzleUriFactory</uri-factory>
             <stream-factory>Http\Message\StreamFactory\GuzzleStreamFactory</stream-factory>
+            <psr18-client>Http\Adapter\Guzzle6\Client</psr18-client>
+            <psr17-request-factory>Nyholm\Psr7\Factory\Psr17Factory</psr17-request-factory>
+            <psr17-response-factory>Nyholm\Psr7\Factory\Psr17Factory</psr17-response-factory>
+            <psr17-stream-factory>Nyholm\Psr7\Factory\Psr17Factory</psr17-stream-factory>
+            <psr17-uri-factory>Nyholm\Psr7\Factory\Psr17Factory</psr17-uri-factory>
+            <psr17-uploaded-file-factory>Nyholm\Psr7\Factory\Psr17Factory</psr17-uploaded-file-factory>
+            <psr17-server-request-factory>Nyholm\Psr7\Factory\Psr17Factory</psr17-server-request-factory>
         </classes>
         <client name="test" factory="httplug.factory.guzzle6" http-methods-client="true">
             <plugin>httplug.plugin.redirect</plugin>
diff --git a/tests/Resources/Fixtures/config/full.yml b/tests/Resources/Fixtures/config/full.yml
index 66f9188f..3074b6c3 100644
--- a/tests/Resources/Fixtures/config/full.yml
+++ b/tests/Resources/Fixtures/config/full.yml
@@ -10,6 +10,13 @@ httplug:
         message_factory: Http\Message\MessageFactory\GuzzleMessageFactory
         uri_factory: Http\Message\UriFactory\GuzzleUriFactory
         stream_factory: Http\Message\StreamFactory\GuzzleStreamFactory
+        psr18_client: Http\Adapter\Guzzle6\Client
+        psr17_request_factory: Nyholm\Psr7\Factory\Psr17Factory
+        psr17_response_factory: Nyholm\Psr7\Factory\Psr17Factory
+        psr17_stream_factory: Nyholm\Psr7\Factory\Psr17Factory
+        psr17_uri_factory: Nyholm\Psr7\Factory\Psr17Factory
+        psr17_uploaded_file_factory: Nyholm\Psr7\Factory\Psr17Factory
+        psr17_server_request_factory: Nyholm\Psr7\Factory\Psr17Factory
     clients:
         test:
             factory: httplug.factory.guzzle6
diff --git a/tests/Unit/DependencyInjection/ConfigurationTest.php b/tests/Unit/DependencyInjection/ConfigurationTest.php
index 129c1c7b..c773c797 100644
--- a/tests/Unit/DependencyInjection/ConfigurationTest.php
+++ b/tests/Unit/DependencyInjection/ConfigurationTest.php
@@ -9,6 +9,7 @@
 use Http\Message\MessageFactory\GuzzleMessageFactory;
 use Http\Message\UriFactory\GuzzleUriFactory;
 use Http\Message\StreamFactory\GuzzleStreamFactory;
+use Nyholm\Psr7\Factory\Psr17Factory;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
 use Symfony\Component\Config\Definition\Exception\InvalidConfigurationException;
 use Symfony\Component\DependencyInjection\Extension\ExtensionInterface;
@@ -25,12 +26,26 @@ class ConfigurationTest extends AbstractExtensionConfigurationTestCase
             'message_factory' => 'httplug.message_factory.default',
             'uri_factory' => 'httplug.uri_factory.default',
             'stream_factory' => 'httplug.stream_factory.default',
+            'psr18_client' => 'httplug.psr18_client.default',
+            'psr17_request_factory' => 'httplug.psr17_request_factory.default',
+            'psr17_response_factory' => 'httplug.psr17_response_factory.default',
+            'psr17_stream_factory' => 'httplug.psr17_stream_factory.default',
+            'psr17_uri_factory' => 'httplug.psr17_uri_factory.default',
+            'psr17_uploaded_file_factory' => 'httplug.psr17_uploaded_file_factory.default',
+            'psr17_server_request_factory' => 'httplug.psr17_server_request_factory.default',
         ],
         'classes' => [
             'client' => null,
+            'psr18_client' => null,
             'message_factory' => null,
             'uri_factory' => null,
             'stream_factory' => null,
+            'psr17_request_factory' => null,
+            'psr17_response_factory' => null,
+            'psr17_stream_factory' => null,
+            'psr17_uri_factory' => null,
+            'psr17_uploaded_file_factory' => null,
+            'psr17_server_request_factory' => null,
         ],
         'clients' => [],
         'profiling' => [
@@ -117,12 +132,26 @@ public function testSupportsAllConfigFormats(): void
                 'message_factory' => 'my_message_factory',
                 'uri_factory' => 'my_uri_factory',
                 'stream_factory' => 'my_stream_factory',
+                'psr18_client' => 'httplug.psr18_client.default',
+                'psr17_request_factory' => 'httplug.psr17_request_factory.default',
+                'psr17_response_factory' => 'httplug.psr17_response_factory.default',
+                'psr17_stream_factory' => 'httplug.psr17_stream_factory.default',
+                'psr17_uri_factory' => 'httplug.psr17_uri_factory.default',
+                'psr17_uploaded_file_factory' => 'httplug.psr17_uploaded_file_factory.default',
+                'psr17_server_request_factory' => 'httplug.psr17_server_request_factory.default',
             ],
             'classes' => [
                 'client' => Client::class,
                 'message_factory' => GuzzleMessageFactory::class,
                 'uri_factory' => GuzzleUriFactory::class,
                 'stream_factory' => GuzzleStreamFactory::class,
+                'psr18_client' => Client::class,
+                'psr17_request_factory' => Psr17Factory::class,
+                'psr17_response_factory' => Psr17Factory::class,
+                'psr17_stream_factory' => Psr17Factory::class,
+                'psr17_uri_factory' => Psr17Factory::class,
+                'psr17_uploaded_file_factory' => Psr17Factory::class,
+                'psr17_server_request_factory' => Psr17Factory::class,
             ],
             'clients' => [
                 'test' => [