diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5ae4131..ef3425a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   merchant portal, and the notification clears once the resolution callback
   updates the stored state.
 
+### Changed
+
+- The test suite runs on PHPUnit 11/12 (`^11.5 || ^12.5`, was the EOL
+  `^10.5`): PHP 8.3+ resolves PHPUnit 12, PHP 8.2 stays on PHPUnit 11.
+  Dev-only - nothing changes for consumers of the plugin.
+
 ### Fixed
 
 - An admin refund rejected by EveryPay because the payment was already
diff --git a/composer.json b/composer.json
index efd1d98..c108d13 100644
--- a/composer.json
+++ b/composer.json
@@ -49,7 +49,7 @@
         "phpstan/extension-installer": "^1.4",
         "phpstan/phpstan": "^2.0",
         "phpstan/phpstan-doctrine": "^2.0",
-        "phpunit/phpunit": "^10.5",
+        "phpunit/phpunit": "^11.5 || ^12.5",
         "sylius-labs/coding-standard": "^4.4",
         "sylius/sylius": "^2.2",
         "sylius/test-application": "^2.2@alpha",
diff --git a/tests/Unit/Provider/EveryPayHttpResponseProviderTest.php b/tests/Unit/Provider/EveryPayHttpResponseProviderTest.php
index 669536f..f9e1f3b 100644
--- a/tests/Unit/Provider/EveryPayHttpResponseProviderTest.php
+++ b/tests/Unit/Provider/EveryPayHttpResponseProviderTest.php
@@ -129,7 +129,7 @@ public function testDoesNotSupportRequestsWithoutAPaymentLink(): void
 
     private function provider(): EveryPayHttpResponseProvider
     {
-        return new EveryPayHttpResponseProvider($this->createMock(Environment::class), new MethodGridViewFactory());
+        return new EveryPayHttpResponseProvider($this->createStub(Environment::class), new MethodGridViewFactory());
     }
 
     private function requestConfiguration(): RequestConfiguration