diff --git a/.github/workflows/quality-assurance.yaml b/.github/workflows/quality-assurance.yaml
index 0d46c32..bc7aea1 100644
--- a/.github/workflows/quality-assurance.yaml
+++ b/.github/workflows/quality-assurance.yaml
@@ -11,7 +11,7 @@ jobs:
         runs-on: ubuntu-latest
         strategy:
             matrix:
-                php: [ '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3' ]
+                php: [ '7.4', '8.0', '8.1', '8.2', '8.3', '8.4' ]
                 composer-flags: [ '' ]
                 phpunit-flags: [ '--coverage-text' ]
         steps:
diff --git a/composer.json b/composer.json
index 602e99e..ef87742 100644
--- a/composer.json
+++ b/composer.json
@@ -21,17 +21,17 @@
         }
     },
     "require": {
-        "php": "^7.1 || ^8.0"
+        "php": "^7.4 || ^8.0"
     },
     "suggest": {
         "psr/http-message": "Common interface for HTTP messages",
         "psr/http-factory": "Common interfaces for PSR-7 HTTP message factories"
     },
     "require-dev": {
+        "nyholm/psr7": "^1.8",
         "phpunit/phpunit": "^7.0 || ^8.0 || ^9.0",
         "psr/http-factory": "^1.0",
         "psr/http-message": "1.*",
-        "laminas/laminas-diactoros": "^2.0",
         "phpstan/phpstan": "^1.3"
     },
     "extra": {
diff --git a/docker/php/81/Dockerfile b/docker/php/81/Dockerfile
index 96acc23..0625db1 100644
--- a/docker/php/81/Dockerfile
+++ b/docker/php/81/Dockerfile
@@ -1,10 +1,8 @@
-FROM php:8.1.1-cli
+FROM php:8.1-cli
 WORKDIR /usr/src/myapp
 
+COPY --from=composer:latest /usr/bin/composer /usr/bin/composer
+
 RUN apt-get update && apt-get install zip unzip git -y \
     && pecl install xdebug \
-    && php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" \
-    && php -r "if (hash_file('sha384', 'composer-setup.php') === '906a84df04cea2aa72f40b5f787e49f22d4c2f19492ac310e8cba5b96ac8b64115ac402c8cd292b8a03482574915d1a8') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;" \
-    && php composer-setup.php --install-dir=/usr/bin --filename=composer \
-    && php -r "unlink('composer-setup.php');" \
-    && mkdir /.composer && chmod 777 /.composer
+    && pecl install pcov
diff --git a/tests/HttpConverterTest.php b/tests/HttpConverterTest.php
index f818996..4de674c 100644
--- a/tests/HttpConverterTest.php
+++ b/tests/HttpConverterTest.php
@@ -4,10 +4,10 @@
 
 namespace Crell\ApiProblem;
 
+use Nyholm\Psr7\Response;
 use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\ResponseFactoryInterface;
 use Psr\Http\Message\ResponseInterface;
-use Laminas\Diactoros\Response;
 
 class HttpConverterTest extends TestCase
 {
@@ -18,7 +18,7 @@ protected function getMockResponseFactory() : ResponseFactoryInterface
         {
             public function createResponse(int $code = 200, string $reasonPhrase = ''): ResponseInterface
             {
-                return new Response('php://memory', $code);
+                return new Response($code);
             }
         };
     }