diff --git a/composer.json b/composer.json
index 22b0327e..70821399 100644
--- a/composer.json
+++ b/composer.json
@@ -34,7 +34,7 @@
         "php": "~8.1.0 || ~8.2.0",
         "laminas/laminas-servicemanager": "^3.21.0",
         "laminas/laminas-stdlib": "^3.13",
-        "psr/http-message": "^1.0.1"
+        "psr/http-message": "^1.0.1 || ^2.0.0"
     },
     "require-dev": {
         "laminas/laminas-coding-standard": "^2.5",
diff --git a/composer.lock b/composer.lock
index fa55e404..0934d181 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "671699eed93da1cc140c6748469431c6",
+    "content-hash": "eb37ce2f739caa3d260d01a63bf8a692",
     "packages": [
         {
             "name": "laminas/laminas-servicemanager",
@@ -206,16 +206,16 @@
         },
         {
             "name": "psr/http-message",
-            "version": "1.1",
+            "version": "2.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/php-fig/http-message.git",
-                "reference": "cb6ce4845ce34a8ad9e68117c10ee90a29919eba"
+                "reference": "402d35bcb92c70c026d1a6a9883f06b2ead23d71"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/php-fig/http-message/zipball/cb6ce4845ce34a8ad9e68117c10ee90a29919eba",
-                "reference": "cb6ce4845ce34a8ad9e68117c10ee90a29919eba",
+                "url": "https://api.github.com/repos/php-fig/http-message/zipball/402d35bcb92c70c026d1a6a9883f06b2ead23d71",
+                "reference": "402d35bcb92c70c026d1a6a9883f06b2ead23d71",
                 "shasum": ""
             },
             "require": {
@@ -224,7 +224,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.1.x-dev"
+                    "dev-master": "2.0.x-dev"
                 }
             },
             "autoload": {
@@ -239,7 +239,7 @@
             "authors": [
                 {
                     "name": "PHP-FIG",
-                    "homepage": "http://www.php-fig.org/"
+                    "homepage": "https://www.php-fig.org/"
                 }
             ],
             "description": "Common interface for HTTP messages",
@@ -253,9 +253,9 @@
                 "response"
             ],
             "support": {
-                "source": "https://github.com/php-fig/http-message/tree/1.1"
+                "source": "https://github.com/php-fig/http-message/tree/2.0"
             },
-            "time": "2023-04-04T09:50:52+00:00"
+            "time": "2023-04-04T09:54:51+00:00"
         }
     ],
     "packages-dev": [
diff --git a/test/UndisclosedPasswordTest.php b/test/UndisclosedPasswordTest.php
index 4da0e462..1b829004 100644
--- a/test/UndisclosedPasswordTest.php
+++ b/test/UndisclosedPasswordTest.php
@@ -15,6 +15,7 @@
 use Psr\Http\Client\ClientInterface;
 use Psr\Http\Message\RequestFactoryInterface;
 use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\StreamInterface;
 use ReflectionClass;
 use stdClass;
 
@@ -26,16 +27,11 @@
 
 final class UndisclosedPasswordTest extends TestCase
 {
-    /** @var ClientInterface&MockObject */
-    private ClientInterface $httpClient;
-
-    /** @var RequestFactoryInterface&MockObject */
-    private RequestFactoryInterface $httpRequest;
-
-    /** @var ResponseInterface&MockObject */
-    private ResponseInterface $httpResponse;
-
+    private ClientInterface&MockObject $httpClient;
+    private RequestFactoryInterface&MockObject $httpRequest;
+    private ResponseInterface&MockObject $httpResponse;
     private UndisclosedPassword $validator;
+    private StreamInterface&MockObject $stream;
 
     /** {@inheritDoc} */
     protected function setUp(): void
@@ -45,8 +41,8 @@ protected function setUp(): void
         $this->httpClient   = $this->createMock(ClientInterface::class);
         $this->httpRequest  = $this->createMock(RequestFactoryInterface::class);
         $this->httpResponse = $this->createMock(ResponseInterface::class);
-
-        $this->validator = new UndisclosedPassword($this->httpClient, $this->httpRequest);
+        $this->validator    = new UndisclosedPassword($this->httpClient, $this->httpRequest);
+        $this->stream       = $this->createMock(StreamInterface::class);
     }
 
     /**
@@ -114,7 +110,7 @@ public function testStrongUnseenPasswordsPassValidation(string $password): void
         $this->httpResponse
             ->expects(self::once())
             ->method('getBody')
-            ->willReturnCallback(function (): string {
+            ->willReturnCallback(function (): StreamInterface {
                 $hash = sha1('laminas-validator');
 
                 $constant = $this->getConstant(
@@ -123,11 +119,14 @@ public function testStrongUnseenPasswordsPassValidation(string $password): void
                 );
                 self::assertIsInt($constant);
 
-                return sprintf(
-                    '%s:%d',
-                    strtoupper(substr($hash, $constant)),
-                    random_int(0, 100000)
-                );
+                $this->stream->method('__toString')
+                    ->willReturn(sprintf(
+                        '%s:%d',
+                        strtoupper(substr($hash, $constant)),
+                        random_int(0, 100000)
+                    ));
+
+                return $this->stream;
             });
 
         $this->httpClient
@@ -148,7 +147,7 @@ public function testBreachedPasswordsDoNotPassValidation(string $password): void
         $this->httpResponse
             ->expects(self::once())
             ->method('getBody')
-            ->willReturnCallback(function () use ($password): string {
+            ->willReturnCallback(function () use ($password): StreamInterface {
                 $hash = sha1($password);
 
                 $constant = $this->getConstant(
@@ -158,11 +157,14 @@ public function testBreachedPasswordsDoNotPassValidation(string $password): void
 
                 self::assertIsInt($constant);
 
-                return sprintf(
-                    '%s:%d',
-                    strtoupper(substr($hash, $constant)),
-                    random_int(0, 100000)
-                );
+                $this->stream->method('__toString')
+                    ->willReturn(sprintf(
+                        '%s:%d',
+                        strtoupper(substr($hash, $constant)),
+                        random_int(0, 100000)
+                    ));
+
+                return $this->stream;
             });
 
         $this->httpClient