diff --git a/.php-cs-fixer.dist.php b/.php-cs-fixer.dist.php
index 3a9284c..1e5d736 100644
--- a/.php-cs-fixer.dist.php
+++ b/.php-cs-fixer.dist.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /*
  * This file is part of PHP CS Fixer / PHPUnit Constraint IsIdenticalString.
  *
@@ -13,13 +15,13 @@
 use PhpCsFixer\Finder;
 
 $header = <<<'EOF'
-This file is part of PHP CS Fixer / PHPUnit Constraint IsIdenticalString.
+    This file is part of PHP CS Fixer / PHPUnit Constraint IsIdenticalString.
 
-(c) Dariusz Rumiński <dariusz.ruminski@gmail.com>
+    (c) Dariusz Rumiński <dariusz.ruminski@gmail.com>
 
-This source file is subject to the MIT license that is bundled
-with this source code in the file LICENSE.
-EOF;
+    This source file is subject to the MIT license that is bundled
+    with this source code in the file LICENSE.
+    EOF;
 
 $finder = Finder::create()
     ->exclude('tests/Fixtures')
@@ -30,9 +32,10 @@
 return (new Config())
     ->setRiskyAllowed(true)
     ->setRules([
+        '@auto' => true,
+        '@auto:risky' => true,
         '@PhpCsFixer' => true,
         '@PhpCsFixer:risky' => true,
-        '@PHPUnit60Migration:risky' => true,
         'header_comment' => ['header' => $header],
     ])
     ->setFinder($finder)
diff --git a/dev-tools/composer.json b/dev-tools/composer.json
index ce71027..bb2c7a8 100644
--- a/dev-tools/composer.json
+++ b/dev-tools/composer.json
@@ -1,12 +1,12 @@
 {
     "require": {
-        "php": "^8.1"
+        "php": "^8.5"
     },
     "require-dev": {
-        "ergebnis/composer-normalize": "*",
-        "maglnet/composer-require-checker": "^3.8",
+        "ergebnis/composer-normalize": "^2.50",
+        "maglnet/composer-require-checker": "^4.21",
         "mi-schi/phpmd-extension": "^4.3",
-        "php-cs-fixer/shim": "^3.68.5",
+        "php-cs-fixer/shim": "^3.94.2",
         "phpmd/phpmd": "^2.15"
     },
     "config": {
diff --git a/src/Constraint/IsIdenticalString.php b/src/Constraint/IsIdenticalString.php
index 331dab0..de789c9 100644
--- a/src/Constraint/IsIdenticalString.php
+++ b/src/Constraint/IsIdenticalString.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /*
  * This file is part of PHP CS Fixer / PHPUnit Constraint IsIdenticalString.
  *
@@ -11,6 +13,4 @@
 
 namespace PhpCsFixer\PhpunitConstraintIsIdenticalString\Constraint;
 
-use PHPUnit\Runner\Version;
-
 class_alias(IsIdenticalStringForV9::class, IsIdenticalString::class);
diff --git a/src/Constraint/IsIdenticalStringForV9.php b/src/Constraint/IsIdenticalStringForV9.php
index 5058a73..197415f 100644
--- a/src/Constraint/IsIdenticalStringForV9.php
+++ b/src/Constraint/IsIdenticalStringForV9.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /*
  * This file is part of PHP CS Fixer / PHPUnit Constraint IsIdenticalString.
  *
diff --git a/tests/Constraint/IsIdenticalStringTest.php b/tests/Constraint/IsIdenticalStringTest.php
index 15cde28..57b2f7b 100644
--- a/tests/Constraint/IsIdenticalStringTest.php
+++ b/tests/Constraint/IsIdenticalStringTest.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /*
  * This file is part of PHP CS Fixer / PHPUnit Constraint IsIdenticalString.
  *
@@ -21,7 +23,7 @@
  */
 final class IsIdenticalStringTest extends TestCase
 {
-    public function testSameStringsConstraintFail()
+    public function testSameStringsConstraintFail(): void
     {
         $this->expectException(
             'PHPUnit\Framework\ExpectationFailedException'
@@ -31,7 +33,7 @@ public function testSameStringsConstraintFail()
                 '#^Failed asserting that two strings are identical\.[\n] \#Warning\: Strings contain different line endings\! Debug using remapping \["\\\r" => "R", "\\\n" => "N", "\\\t" => "T"\]\:\n \-N\n \+RN$#'
             );
         } else {
-            $this->expectExceptionMessageRegExp(
+            $this->expectExceptionMessageMatches(
                 '#^Failed asserting that two strings are identical\.[\n] \#Warning\: Strings contain different line endings\! Debug using remapping \["\\\r" => "R", "\\\n" => "N", "\\\t" => "T"\]\:\n \-N\n \+RN$#'
             );
         }