diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index b7a4afc..c3ac085 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: ['8.2', '8.3', '8.4', '8.5']
+        php-version: ['8.3', '8.4', '8.5']
 
     uses: simplesamlphp/simplesamlphp-test-framework/.github/workflows/reusable_phplinter.yml@v1.10.6
     with:
@@ -44,7 +44,7 @@ jobs:
       fail-fast: false
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['8.2', '8.3', '8.4', '8.5']
+        php-versions: ['8.3', '8.4', '8.5']
 
     steps:
       - name: Setup PHP, with composer and extensions
@@ -107,7 +107,7 @@ jobs:
       fail-fast: true
       matrix:
         operating-system: [windows-latest]
-        php-versions: ['8.2', '8.3', '8.4', '8.5']
+        php-versions: ['8.3', '8.4', '8.5']
 
     steps:
       - name: Setup PHP, with composer and extensions
@@ -225,7 +225,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           # Should be the lowest supported version
-          php-version: '8.2'
+          php-version: '8.3'
           extensions: ctype, date, dom, filter, hash, intl, mbstring, openssl, pcre, spl, xml
           tools: composer
           coverage: none
diff --git a/.github/workflows/reusable_phplinter.yml b/.github/workflows/reusable_phplinter.yml
index c96d1d1..c7ce48c 100644
--- a/.github/workflows/reusable_phplinter.yml
+++ b/.github/workflows/reusable_phplinter.yml
@@ -19,7 +19,7 @@ on:  # yamllint disable-line rule:truthy
         default: ${{ github.ref }}
 
 env:
-  supported: '["7.4", "8.0", "8.1", "8.2", "8.3", "8.4", "8.5"]'
+  supported: '["8.3", "8.4", "8.5"]'
 
 jobs:
   linter:
@@ -45,29 +45,10 @@ jobs:
           coverage: "none"
           extensions: :redis
 
-      - name: Install overtrue/phplint (v3.4)
-        if: inputs.php-version == '7.4'
+      - name: Install overtrue/phplint (v9.7)
         run: |
           sleep $((random % 10))
-          phive install overtrue/phplint@~3.4.0 --force-accept-unsigned --target ./bin
-
-      - name: Install overtrue/phplint (v4.5)
-        if: inputs.php-version == '8.0'
-        run: |
-          sleep $((random % 10))
-          phive install overtrue/phplint@~4.5.0 --force-accept-unsigned --target ./bin
-
-      - name: Install overtrue/phplint (v9.4)
-        if: inputs.php-version == '8.1'
-        run: |
-          sleep $((random % 10))
-          phive install overtrue/phplint@~9.4.0 --force-accept-unsigned --target ./bin
-
-      - name: Install overtrue/phplint (v9.6)
-        if: inputs.php-version != '7.4' && inputs.php-version != '8.0' && inputs.php-version != '8.1'
-        run: |
-          sleep $((random % 10))
-          phive install overtrue/phplint@~9.6.0 --force-accept-unsigned --target ./bin
+          phive install overtrue/phplint@~9.7.1 --force-accept-unsigned --target ./bin
 
       - name: Lint PHP files
         run: |
diff --git a/composer.json b/composer.json
index bd4b845..a2073af 100644
--- a/composer.json
+++ b/composer.json
@@ -21,20 +21,20 @@
         }
     },
     "require": {
-        "php": "^8.2",
+        "php": "^8.3",
         "ext-curl": "*",
 
         "icanhazstring/composer-unused": "^0.9",
-        "maglnet/composer-require-checker": "^4",
+        "maglnet/composer-require-checker": "^4.19",
         "phpstan/extension-installer": "^1.4",
         "phpstan/phpstan": "^2.1",
         "phpstan/phpstan-mockery": "^2.0",
         "phpstan/phpstan-phpunit": "^2.0",
-        "phpunit/phpunit": "^11.5 || ^12.3",
+        "phpunit/phpunit": "^12.3",
         "psr/log": "^3.0",
-        "slevomat/coding-standard": "^8.20",
+        "slevomat/coding-standard": "^8.25",
         "squizlabs/php_codesniffer": "^4.0",
-        "symfony/phpunit-bridge": "^7.3 || ^8.0"
+        "symfony/phpunit-bridge": "^8.0"
     },
     "require-dev": {
         "simplesamlphp/simplesamlphp": "^2.5@dev"
diff --git a/lib/ArrayLogger.php b/lib/ArrayLogger.php
index 04d07db..40e2f6c 100644
--- a/lib/ArrayLogger.php
+++ b/lib/ArrayLogger.php
@@ -8,7 +8,6 @@
 use SimpleSAML\Logger\LoggingHandlerInterface;
 
 /**
- * @deprecated - superseeded by PSR-3 compliant SimpleTestLogger
  */
 class ArrayLogger implements LoggingHandlerInterface
 {
@@ -18,6 +17,7 @@ class ArrayLogger implements LoggingHandlerInterface
     public array $logs = [];
 
 
+    #[\Deprecated('Superseeded by PSR-3 compliant SimpleTestLogger', '20-05-2023')]
     public function __construct(Configuration $config)
     {
         // don't do anything with the configuration
diff --git a/lib/BuiltInServer.php b/lib/BuiltInServer.php
index 34bf8d8..ed3a2ce 100644
--- a/lib/BuiltInServer.php
+++ b/lib/BuiltInServer.php
@@ -41,31 +41,23 @@ class BuiltInServer
 {
     /**
      * The PID of the running server.
-     *
-     * @var int
      */
-    protected $pid = 0;
+    protected int $pid = 0;
 
     /**
      * The address (host:port) where the server is listening for connections after being started.
-     *
-     * @var string
      */
-    protected $address = 'example.org';
+    protected string $address = 'example.org';
 
     /**
      * The name of a "router" file to run for every request performed to this server.
-     *
-     * @var string
      */
-    protected $router = '';
+    protected string $router = '';
 
     /**
      * The document root of the server.
-     *
-     * @var string
      */
-    protected $docroot;
+    protected string $docroot;
 
 
     /**
@@ -158,7 +150,6 @@ public function start(): string
 
     /**
      * Stop the built-in server.
-     * @return void
      */
     public function stop(): void
     {
@@ -200,7 +191,6 @@ public function getRouter(): string
      * Set the "router" file.
      *
      * @param string $router The name of a "router" file to use when starting the server.
-     * @return void
      */
     public function setRouter(string $router): void
     {
diff --git a/lib/ClearStateTestCase.php b/lib/ClearStateTestCase.php
index f66ca44..46380b3 100644
--- a/lib/ClearStateTestCase.php
+++ b/lib/ClearStateTestCase.php
@@ -13,13 +13,11 @@ class ClearStateTestCase extends TestCase
 {
     /**
      * Used for managing and clearing state
-     * @var \SimpleSAML\TestUtils\StateClearer|null
      */
-    protected static $stateClearer = null;
+    protected static ?StateClearer $stateClearer = null;
 
 
     /**
-     * @return void
      */
     public static function setUpBeforeClass(): void
     {
@@ -31,7 +29,6 @@ public static function setUpBeforeClass(): void
 
 
     /**
-     * @return void
      */
     protected function setUp(): void
     {
@@ -40,7 +37,6 @@ protected function setUp(): void
 
 
     /**
-     * @return void
      */
     public static function tearDownAfterClass(): void
     {
@@ -50,7 +46,6 @@ public static function tearDownAfterClass(): void
 
     /**
      * Clear any SSP global state to reduce spill over between tests.
-     * @return void
      */
     public static function clearState(): void
     {
diff --git a/lib/ReduceSpillOverTest.php b/lib/ReduceSpillOverTest.php
index 542b22c..de0ad44 100644
--- a/lib/ReduceSpillOverTest.php
+++ b/lib/ReduceSpillOverTest.php
@@ -9,13 +9,13 @@
 
 /**
  * Test that ensures state doesn't spill over between tests
+ *
  * @package SimpleSAML\Test\Utils
  */
 class ReduceSpillOverTest extends ClearStateTestCase
 {
     /**
      * Set some global state
-     * @return void
      */
     public function testSetState(): void
     {
@@ -28,7 +28,7 @@ public function testSetState(): void
 
     /**
      * Confirm global state removed prior to next test
-     * @return void
+     *
      * @throws \SimpleSAML\Error\ConfigurationError
      */
     public function testStateRemoved(): void
diff --git a/lib/SigningTestCase.php b/lib/SigningTestCase.php
index 3df76fc..620ef4d 100644
--- a/lib/SigningTestCase.php
+++ b/lib/SigningTestCase.php
@@ -16,42 +16,31 @@
  */
 class SigningTestCase extends TestCase
 {
-    /** @var \SimpleSAML\Configuration */
-    protected $config;
+    protected Configuration $config;
 
-    /** @var string $root_directory */
-    protected $root_directory;
+    protected string $root_directory;
 
-    /** @var string $cert_directory */
-    protected $cert_directory = 'certificates/rsa-pem';
+    protected string $cert_directory = 'certificates/rsa-pem';
 
-    /** @var string $ca_private_key_file */
-    protected $ca_private_key_file = 'simplesamlphp.org-ca_nopasswd.key';
+    protected string $ca_private_key_file = 'simplesamlphp.org-ca_nopasswd.key';
 
-    /** @var string $ca_certificate_file */
-    protected $ca_certificate_file = 'simplesamlphp.org-ca.crt';
+    protected string $ca_certificate_file = 'simplesamlphp.org-ca.crt';
 
-    /** @var string $good_private_key_file */
-    protected $good_private_key_file = 'signed.simplesamlphp.org_nopasswd.key';
+    protected string $good_private_key_file = 'signed.simplesamlphp.org_nopasswd.key';
 
-    /** @var string $good_certificate_file */
-    protected $good_certificate_file = 'signed.simplesamlphp.org.crt';
+    protected string $good_certificate_file = 'signed.simplesamlphp.org.crt';
 
     // openssl genrsa -out example.org-ca.key 1024
-    /** @var string $ca_private_key */
-    protected $ca_private_key;
+    protected string $ca_private_key;
 
     // openssl req -key example.org-ca.key -new -x509 -days 36500 -out example.org-ca.crt
-    /** @var string $ca_certificate */
-    protected $ca_certificate;
+    protected string $ca_certificate;
 
     // openssl genrsa -out signed.example.org.key 1024
-    /** @var string $good_private_key */
-    protected $good_private_key;
+    protected string $good_private_key;
 
     // openssl req -key signed.example.org.key -new -out signed.example.org.crt
-    /** @var string $good_certificate */
-    protected $good_certificate;
+    protected string $good_certificate;
 
 
     /**
@@ -69,7 +58,6 @@ public function __construct()
 
 
     /**
-     * @return array
      */
     public function getCertDirContent(): array
     {
@@ -83,7 +71,6 @@ public function getCertDirContent(): array
 
 
     /**
-     * @return void
      */
     public function setUp(): void
     {
@@ -94,7 +81,6 @@ public function setUp(): void
 
 
     /**
-     * @return void
      */
     public function tearDown(): void
     {
@@ -106,7 +92,6 @@ public function tearDown(): void
      * @param \SimpleSAML\Configuration $service
      * @param class-string $className
      * @param mixed|null $value
-     * @return void
      */
     protected function clearInstance(Configuration $service, string $className, $value = null): void
     {
diff --git a/lib/SimpleTestLogger.php b/lib/SimpleTestLogger.php
index 18b123a..6e5a429 100644
--- a/lib/SimpleTestLogger.php
+++ b/lib/SimpleTestLogger.php
@@ -18,7 +18,6 @@
 final class SimpleTestLogger extends AbstractLogger
 {
     /**
-     * @var array
      */
     private array $messages = [];
 
@@ -27,8 +26,6 @@ final class SimpleTestLogger extends AbstractLogger
      * @param mixed $level
      * @param string|\Stringable $message
      * @param mixed[] $context
-     *
-     * @return void
      */
     public function log($level, string|Stringable $message, array $context = []): void
     {
@@ -44,8 +41,6 @@ public function log($level, string|Stringable $message, array $context = []): vo
      * Get all the messages logged at the specified level
      *
      * @param mixed $level
-     *
-     * @return array
      */
     public function getMessagesForLevel($level): array
     {
@@ -59,8 +54,6 @@ public function getMessagesForLevel($level): array
      * Check if the given message exists within the log
      *
      * @param string|\Stringable $messageToFind
-     *
-     * @return bool
      */
     public function hasMessage(string|Stringable $messageToFind): bool
     {
diff --git a/lib/StateClearer.php b/lib/StateClearer.php
index b610608..7d5263f 100644
--- a/lib/StateClearer.php
+++ b/lib/StateClearer.php
@@ -16,15 +16,13 @@ class StateClearer
 {
     /**
      * Global state to restore between test runs
-     * @var array
      */
-    private $backups = [];
+    private array $backups = [];
 
     /**
      * Class that implement \SimpleSAML\Utils\ClearableState and should have clearInternalState called between tests
-     * @var array
      */
-    private $clearableState = [
+    private array $clearableState = [
         Configuration::class,
         MetaDataStorageHandler::class,
         Session::class,
@@ -33,15 +31,13 @@ class StateClearer
 
     /**
      * Environmental variables to unset
-     * @var array
      */
-    private $vars_to_unset = ['SIMPLESAMLPHP_CONFIG_DIR'];
+    private array $vars_to_unset = ['SIMPLESAMLPHP_CONFIG_DIR'];
 
 
     /**
-     * @return void
      */
-    public function backupGlobals()
+    public function backupGlobals(): void
     {
         // Backup any state that is needed as part of processing, so we can restore it later.
         // TODO: phpunit's backupGlobals = false, yet we are trying to do a similar thing here. Is that an issue?
@@ -51,7 +47,6 @@ public function backupGlobals()
         $this->backups['$_GET'] = $_GET;
         $this->backups['$_POST'] = $_POST;
         $this->backups['$_SERVER'] = $_SERVER;
-        /** @psalm-suppress RedundantCondition */
         $this->backups['$_SESSION'] = isset($_SESSION) ? $_SESSION : [];
         $this->backups['$_REQUEST'] = $_REQUEST;
     }
@@ -59,9 +54,8 @@ public function backupGlobals()
 
     /**
      * Clear any global state.
-     * @return void
      */
-    public function clearGlobals()
+    public function clearGlobals(): void
     {
         if (!empty($this->backups)) {
             $_COOKIE = $this->backups['$_COOKIE'];
@@ -80,9 +74,8 @@ public function clearGlobals()
 
     /**
      * Clear any SSP specific state, such as SSP enviormental variables or cached internals.
-     * @return void
      */
-    public function clearSSPState()
+    public function clearSSPState(): void
     {
         foreach ($this->clearableState as $var) {
             $var::clearInternalState();
diff --git a/phpcs-simplesamlphp.xml b/phpcs-simplesamlphp.xml
index d8b92b5..97c4617 100644
--- a/phpcs-simplesamlphp.xml
+++ b/phpcs-simplesamlphp.xml
@@ -29,6 +29,9 @@
   <rule ref="SlevomatCodingStandard.Functions.RequireTrailingCommaInClosureUse" />
   <rule ref="SlevomatCodingStandard.Functions.RequireTrailingCommaInDeclaration" />
 
+  <!-- Enforce the use of typed constants -->
+  <rule ref="SlevomatCodingStandard.TypeHints.ClassConstantTypeHint" />
+
   <!-- Require one blank line between different types of use-statements -->
   <rule ref="SlevomatCodingStandard.Namespaces.UseSpacing">
     <properties>
diff --git a/src/TemplateTest.php b/src/TemplateTest.php
index 3abc98a..37481e4 100644
--- a/src/TemplateTest.php
+++ b/src/TemplateTest.php
@@ -16,13 +16,10 @@
  *
  * @author Tim van Dijen <tvdijen@gmail.com>
  * @package SimpleSAMLphp
- *
- * @psalm-suppress InternalMethod
  */
 class TemplateTest extends TestCase
 {
     /**
-     * @return void
      */
     public function testSyntax(): void
     {