diff --git a/composer.json b/composer.json
index d53502e..0b7b1ac 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         "php": "~8.4.0 || ~8.5.0"
     },
     "require-dev": {
-        "phpstan/phpstan": "^2.1.39",
+        "phpstan/phpstan": "^2.1.40",
         "phpstan/phpstan-phpunit": "^2.0.16",
         "phpstan/phpstan-strict-rules": "^2.0.10",
         "phpunit/phpunit": "^13.0.5",
diff --git a/phpunit.xml b/phpunit.xml
index c4e48f9..bc69f01 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -4,8 +4,9 @@
         xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
         colors="true"
         cacheDirectory=".phpunit.cache"
-        displayDetailsOnPhpunitDeprecations="true"
-        displayDetailsOnTestsThatTriggerDeprecations="true"
+        failOnAllIssues="true"
+        displayDetailsOnAllIssues="true"
+        beStrictAboutChangesToGlobalState="true"
 >
   <coverage>
     <report>
diff --git a/tests/ErrorHandlerTest.php b/tests/ErrorHandlerTest.php
index cbfd67a..392f9a3 100644
--- a/tests/ErrorHandlerTest.php
+++ b/tests/ErrorHandlerTest.php
@@ -189,8 +189,10 @@ public function testEmailException(): void
         $this->errorHandler->emailException($this->exception);
 
         self::assertNotEmpty($this->emailsSent);
-        $message     = \current($this->emailsSent);
+        $message     = $this->emailsSent[0];
+        self::assertIsArray($message);
         $messageText = $message['body'];
+        self::assertIsString($messageText);
         self::assertStringContainsString($this->exception->getMessage(), $messageText);
         self::assertStringContainsString($_SESSION[$key], $messageText);
         self::assertStringContainsString($_POST[$key], $messageText);