diff --git a/composer.json b/composer.json
index 6eae5a81..7b8d8eb9 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,8 @@
         },
         "allow-plugins": {
             "composer/package-versions-deprecated": true,
-            "simplesamlphp/composer-module-installer": true
+            "simplesamlphp/composer-module-installer": true,
+            "dealerdirect/phpcodesniffer-composer-installer": true
         }
     },
     "autoload": {
@@ -26,10 +27,10 @@
         }
     },
     "require": {
-        "php": "^8.0",
+        "php": "^8.1",
 
         "simplesamlphp/composer-module-installer": "^1.3.4",
-        "simplesamlphp/simplesamlphp": "^3@dev",
+        "simplesamlphp/simplesamlphp": "^2.1",
         "simplesamlphp/xml-cas": "^1.0.3",
         "simplesamlphp/xml-common": "^1.12.2",
         "simplesamlphp/xml-soap": "^1.3.0"
diff --git a/phpcs.xml b/phpcs.xml
index 830c227f..511ab865 100644
--- a/phpcs.xml
+++ b/phpcs.xml
@@ -6,7 +6,7 @@
         By default it is less stringent about long lines than other coding standards
     </description>
 
-    <file>config-templates</file>
+    <file>config</file>
     <file>public</file>
     <file>src</file>
     <file>templates</file>
diff --git a/public/cas.php b/public/cas.php
index 22271dab..6c9f6028 100644
--- a/public/cas.php
+++ b/public/cas.php
@@ -26,6 +26,8 @@
  *
  */
 
+declare(strict_types=1);
+
 $validFunctions = [
     'login' => 'login',
     'validate' => 'validate',
diff --git a/public/loggedIn.php b/public/loggedIn.php
index 0ca209ec..295f4821 100644
--- a/public/loggedIn.php
+++ b/public/loggedIn.php
@@ -21,6 +21,8 @@
  *
  */
 
+declare(strict_types=1);
+
 session_cache_limiter('nocache');
 
 $globalConfig = \SimpleSAML\Configuration::getInstance();
diff --git a/public/loggedOut.php b/public/loggedOut.php
index cb5430eb..20330c68 100644
--- a/public/loggedOut.php
+++ b/public/loggedOut.php
@@ -21,6 +21,8 @@
  *
  */
 
+declare(strict_types=1);
+
 session_cache_limiter('nocache');
 
 $globalConfig = \SimpleSAML\Configuration::getInstance();
diff --git a/public/login.php b/public/login.php
index 7adfa082..dfc3c74e 100644
--- a/public/login.php
+++ b/public/login.php
@@ -28,15 +28,15 @@
  *  language
  */
 
-use SimpleSAML\Module\casserver\Cas\AttributeExtractor;
-use SimpleSAML\Module\casserver\Cas\Protocol\SamlValidateResponder;
-use SimpleSAML\Module\casserver\Cas\ServiceValidator;
-use SimpleSAML\Module\casserver\Cas\Ticket\TicketFactory;
-use SimpleSAML\Module\casserver\Cas\Ticket\TicketStore;
+declare(strict_types=1);
+
 use SimpleSAML\Configuration;
 use SimpleSAML\Locale\Language;
 use SimpleSAML\Logger;
 use SimpleSAML\Module;
+use SimpleSAML\Module\casserver\Cas\AttributeExtractor;
+use SimpleSAML\Module\casserver\Cas\Protocol\SamlValidateResponder;
+use SimpleSAML\Module\casserver\Cas\ServiceValidator;
 use SimpleSAML\Session;
 use SimpleSAML\Utils;
 
diff --git a/public/logout.php b/public/logout.php
index 6a3b2e23..64307f0c 100644
--- a/public/logout.php
+++ b/public/logout.php
@@ -23,6 +23,8 @@
  *  url     - optional if a logout page is displayed
  */
 
+declare(strict_types=1);
+
 /* Load simpleSAMLphp, configuration and metadata */
 $casconfig = \SimpleSAML\Configuration::getConfig('module_casserver.php');
 
diff --git a/public/proxy.php b/public/proxy.php
index 7c0584b5..f7cc5729 100644
--- a/public/proxy.php
+++ b/public/proxy.php
@@ -25,6 +25,8 @@
  *
  */
 
+declare(strict_types=1);
+
 require_once('utility/urlUtils.php');
 
 $casconfig = \SimpleSAML\Configuration::getConfig('module_casserver.php');
diff --git a/public/proxyValidate.php b/public/proxyValidate.php
index 9349e0e2..01ab183d 100644
--- a/public/proxyValidate.php
+++ b/public/proxyValidate.php
@@ -26,6 +26,8 @@
  *  pgtUrl
  */
 
+declare(strict_types=1);
+
 $method = 'proxyValidate';
 
 require_once('utility/validateTicket.php');
diff --git a/public/samlValidate.php b/public/samlValidate.php
index 5574b3d8..fdb50128 100644
--- a/public/samlValidate.php
+++ b/public/samlValidate.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use SimpleSAML\Logger;
 use SimpleSAML\Module\casserver\Cas\Protocol\SamlValidateResponder;
 
diff --git a/public/serviceValidate.php b/public/serviceValidate.php
index 64f08354..8697a196 100644
--- a/public/serviceValidate.php
+++ b/public/serviceValidate.php
@@ -26,6 +26,8 @@
  *  pgtUrl
  */
 
+declare(strict_types=1);
+
 $method = 'serviceValidate';
 
 require_once('utility/validateTicket.php');
diff --git a/public/utility/validateTicket.php b/public/utility/validateTicket.php
index 00d9ef36..e9ca543c 100644
--- a/public/utility/validateTicket.php
+++ b/public/utility/validateTicket.php
@@ -33,9 +33,6 @@
 use SimpleSAML\Configuration;
 use SimpleSAML\Logger;
 use SimpleSAML\Module;
-use SimpleSAML\Module\casserver\Cas\Protocol\Cas20;
-use SimpleSAML\Module\casserver\Cas\Ticket\TicketFactory;
-use SimpleSAML\Module\casserver\Cas\Ticket\TicketStore;
 use SimpleSAML\Utils;
 use SimpleSAML\XML\CAS\Constants as C;
 
diff --git a/public/validate.php b/public/validate.php
index 3f85721a..ee4059e1 100644
--- a/public/validate.php
+++ b/public/validate.php
@@ -26,6 +26,8 @@
  *
  */
 
+declare(strict_types=1);
+
 require_once('utility/urlUtils.php');
 
 /* Load simpleSAMLphp, configuration and metadata */
diff --git a/src/Cas/Protocol/Cas20.php b/src/Cas/Protocol/Cas20.php
index c359eb88..250d0442 100644
--- a/src/Cas/Protocol/Cas20.php
+++ b/src/Cas/Protocol/Cas20.php
@@ -25,9 +25,6 @@
 
 namespace SimpleSAML\Module\casserver\Cas\Protocol;
 
-use DOMDocument;
-use DOMElement;
-use DOMException;
 use SimpleSAML\CAS\XML\cas\Attributes;
 use SimpleSAML\CAS\XML\cas\AuthenticationDate;
 use SimpleSAML\CAS\XML\cas\AuthenticationFailure;
@@ -51,7 +48,6 @@
 use function filter_var;
 use function is_null;
 use function is_string;
-use function strval;
 use function str_replace;
 
 class Cas20
diff --git a/src/Cas/TicketValidator.php b/src/Cas/TicketValidator.php
index 1b9e0070..372371ef 100644
--- a/src/Cas/TicketValidator.php
+++ b/src/Cas/TicketValidator.php
@@ -6,7 +6,6 @@
 
 use InvalidArgumentException;
 use SimpleSAML\Configuration;
-use SimpleSAML\Error\BadRequest;
 use SimpleSAML\Logger;
 use SimpleSAML\Module;
 use SimpleSAML\Module\casserver\Cas\CasException;
diff --git a/tests/config/authsources.php b/tests/config/authsources.php
index a42ecf7c..58bcb49f 100644
--- a/tests/config/authsources.php
+++ b/tests/config/authsources.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 $config = [
     'admin' => [
         'core:AdminPassword',
diff --git a/tests/config/module_casserver.php b/tests/config/module_casserver.php
index 9d1dc0f3..ee486276 100644
--- a/tests/config/module_casserver.php
+++ b/tests/config/module_casserver.php
@@ -5,6 +5,8 @@
  *
  */
 
+declare(strict_types=1);
+
 $config = [
     'authsource' => 'casserver',
 
diff --git a/tests/public/LoginIntegrationTest.php b/tests/public/LoginIntegrationTest.php
index 66e77e6d..5231753b 100644
--- a/tests/public/LoginIntegrationTest.php
+++ b/tests/public/LoginIntegrationTest.php
@@ -7,7 +7,6 @@
 use DOMDocument;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\Configuration;
-use SimpleSAML\Logger;
 use SimpleSAML\TestUtils\BuiltInServer;
 use SimpleSAML\XML\DOMDocumentFactory;
 
diff --git a/tests/src/Ticket/DelegatingTicketStoreTest.php b/tests/src/Ticket/DelegatingTicketStoreTest.php
index 893bf139..db6f7b98 100644
--- a/tests/src/Ticket/DelegatingTicketStoreTest.php
+++ b/tests/src/Ticket/DelegatingTicketStoreTest.php
@@ -63,7 +63,7 @@ public function setup(): void
         );
         Configuration::setPreLoadedConfig($this->config, 'config.php');
 
-        $this->ticketstoreConfig = array(
+        $this->ticketstoreConfig = [
             'delegateTo' => 'all',
             'ticketStores' => [
                 'name1' => [
@@ -82,7 +82,7 @@ public function setup(): void
                     'directory' => 'does-not-exist',
                 ],
             ]
-        );
+        ];
 
         $this->fileStore1 = new FileSystemTicketStore(
             Configuration::loadFromArray(['ticketstore' => $this->ticketstoreConfig['ticketStores']['name1']])
@@ -176,14 +176,14 @@ public function testNamed(): void
      */
     public function testDelegateErrorsIfNoSuccess(): void
     {
-        $config = array(
+        $config = [
             'delegateTo' => 'all',
             'ticketStores' => [
                 'error' => [
                     'class' => ErroringTicketStore::class
                 ]
             ]
-        );
+        ];
 
         $ticketStore = new DelegatingTicketStore(Configuration::loadFromArray(['ticketstore' => $config]));
         try {