diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 0f1ccaa..f16b707 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -12,14 +12,14 @@ on:
 jobs:
     testsuite:
         name: Unittests
-        runs-on: ubuntu-20.04
+        runs-on: ubuntu-22.04
         strategy:
             fail-fast: false
             matrix:
-                php-version: ['8.0', '8.1', '8.2']
+                php-version: ['8.1', '8.2', '8.3']
 
         steps:
-            - uses: actions/checkout@v2
+            - uses: actions/checkout@v4
               with:
                   fetch-depth: 1
 
@@ -27,7 +27,7 @@ jobs:
               uses: shivammathur/setup-php@v2
               with:
                   php-version: ${{ matrix.php-version }}
-                  extensions: json, pdo
+                  extensions: json, mbstring
                   tools: pecl
 
             - name: Validate composer.json
diff --git a/.gitignore b/.gitignore
index 5c9fe27..06b17b2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -81,3 +81,4 @@ Network Trash Folder
 Temporary Items
 .apdisk
 /.phpunit.result.cache
+/.phpunit.cache
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c0a0373..8ab9341 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,13 @@
 Change Log
 ==========
 
+2024-03-02
+----------
+
+ * required PHP 8.1+
+ * update dependencies
+ * fix missing return types
+
 2023-10-05
 ----------
 
diff --git a/composer.json b/composer.json
index 8df3f74..9727b76 100644
--- a/composer.json
+++ b/composer.json
@@ -15,11 +15,11 @@
         }
     ],
     "require": {
-        "php": ">=8.0",
+        "php": ">=8.1",
         "ext-mbstring": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.5",
+        "phpunit/phpunit": "^10.5",
         "doctrine/dbal": "^3.1.0",
         "ramsey/uuid": "^4.3",
         "symfony/var-dumper": "^6.0"
diff --git a/phpunit.xml b/phpunit.xml
index 815a57c..2e79f20 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,15 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- https://phpunit.de/manual/current/en/appendixes.configuration.html -->
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.5/phpunit.xsd"
-         backupGlobals="false" colors="true" bootstrap="vendor/autoload.php">
-    <coverage processUncoveredFiles="true">
-        <include>
-            <directory suffix=".php">src/</directory>
-        </include>
-        <exclude>
-            <directory>tests</directory>
-        </exclude>
-    </coverage>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd"
+         backupGlobals="false" colors="true" bootstrap="vendor/autoload.php" cacheDirectory=".phpunit.cache">
     <php>
         <ini name="error_reporting" value="-1"/>
         <ini name="memory_limit" value="256M"/>
@@ -19,4 +11,12 @@
             <directory>tests</directory>
         </testsuite>
     </testsuites>
+    <source>
+        <include>
+            <directory suffix=".php">src/</directory>
+        </include>
+        <exclude>
+            <directory>tests</directory>
+        </exclude>
+    </source>
 </phpunit>
diff --git a/src/Factory.php b/src/Factory.php
index 544127e..ef1c5f1 100644
--- a/src/Factory.php
+++ b/src/Factory.php
@@ -39,7 +39,7 @@ public function __invoke(string $rule, ...$args): Rule
         return $this->rule($rule)->fillParameters($args);
     }
 
-    protected function registerDefaultRules()
+    protected function registerDefaultRules(): void
     {
         $rules = [
             'accepted'                 => new Rules\Accepted,
diff --git a/src/Rules/Present.php b/src/Rules/Present.php
index a536f20..96bc30e 100644
--- a/src/Rules/Present.php
+++ b/src/Rules/Present.php
@@ -16,7 +16,7 @@ public function check(mixed $value): bool
         return $this->validation->input()->has($this->attribute->key());
     }
 
-    protected function setAttributeAsRequired()
+    protected function setAttributeAsRequired(): void
     {
         $this->attribute?->makeRequired();
     }
diff --git a/tests/FactoryTest.php b/tests/FactoryTest.php
index 5ac084f..f3244a9 100644
--- a/tests/FactoryTest.php
+++ b/tests/FactoryTest.php
@@ -85,10 +85,13 @@ public function testNonExistentValidationRule()
     public function testNewValidationRuleCanBeAdded()
     {
         $this->validator->addRule('even', new Even());
+        $this->validator->messages()->add('en', [
+            'rule.even' => 'The :attribute must be even',
+        ]);
 
-        $data = [4, 6, 8, 10 ];
+        $data = ['s' => 4];
 
-        $validation = $this->validator->make($data, ['s' => 'even'], []);
+        $validation = $this->validator->make($data, ['s' => 'even']);
 
         $validation->validate();
 
@@ -312,7 +315,7 @@ public function testRootAsteriskValidation(array $data, array $rules, $errors =
         }
     }
 
-    public function rootAsteriskProvider(): array
+    public static function rootAsteriskProvider(): array
     {
         return [
             'control sample success' => [
diff --git a/tests/Fixtures/Even.php b/tests/Fixtures/Even.php
index 6460be8..300d30e 100644
--- a/tests/Fixtures/Even.php
+++ b/tests/Fixtures/Even.php
@@ -6,7 +6,7 @@
 
 class Even extends Rule
 {
-    protected string $message = "The :attribute must be even";
+    protected string $message = 'rule.even';
 
     public function check($value): bool
     {
diff --git a/tests/Rules/AfterTest.php b/tests/Rules/AfterTest.php
index f9985ea..1232a95 100644
--- a/tests/Rules/AfterTest.php
+++ b/tests/Rules/AfterTest.php
@@ -12,7 +12,7 @@ class AfterTest extends TestCase
 {
 
     /**
-     * @var \Somnambulist\Components\Validation\Rules\After
+     * @var After
      */
     protected $validator;
 
@@ -48,7 +48,7 @@ public function testUserProvidedParamCannotBeValidatedBecauseItIsInvalid()
         $this->validator->fillParameters(["to,morrow"])->check("now");
     }
 
-    public function getInvalidDates()
+    public static function getInvalidDates(): array
     {
         $now = new DateTime();
 
@@ -62,7 +62,7 @@ public function getInvalidDates()
         ];
     }
 
-    public function getValidDates()
+    public static function getValidDates(): array
     {
         $now = new DateTime();
 
diff --git a/tests/Rules/BeforeTest.php b/tests/Rules/BeforeTest.php
index 669ecfb..b34bc6a 100644
--- a/tests/Rules/BeforeTest.php
+++ b/tests/Rules/BeforeTest.php
@@ -30,7 +30,7 @@ public function testOnlyAWellFormedDateCanBeValidated($date)
         );
     }
 
-    public function getValidDates()
+    public static function getValidDates(): array
     {
         $now = new DateTime();
 
@@ -54,7 +54,7 @@ public function testANonWellFormedDateCannotBeValidated($date)
         $this->validator->fillParameters(["tomorrow"])->check($date);
     }
 
-    public function getInvalidDates()
+    public static function getInvalidDates(): array
     {
         $now = new DateTime();
 
diff --git a/tests/Rules/BooleanTest.php b/tests/Rules/BooleanTest.php
index 237d9ff..1ee72b3 100644
--- a/tests/Rules/BooleanTest.php
+++ b/tests/Rules/BooleanTest.php
@@ -17,8 +17,8 @@ public function setUp(): void
 
     public function testValids()
     {
-        $this->assertTrue($this->rule->check(\true));
-        $this->assertTrue($this->rule->check(\false));
+        $this->assertTrue($this->rule->check(true));
+        $this->assertTrue($this->rule->check(false));
         $this->assertTrue($this->rule->check(1));
         $this->assertTrue($this->rule->check(0));
         $this->assertTrue($this->rule->check('1'));
diff --git a/tests/UploadedFileTest.php b/tests/UploadedFileTest.php
index 6274b3f..1aed50e 100644
--- a/tests/UploadedFileTest.php
+++ b/tests/UploadedFileTest.php
@@ -74,7 +74,7 @@ public function testMissingKeyUploadedFile($uploadedFile)
         $this->assertNotNull($errors->first('file:required'));
     }
 
-    public function getSamplesMissingKeyFromUploadedFileValue()
+    public static function getSamplesMissingKeyFromUploadedFileValue(): array
     {
         $validUploadedFile = [
             'name' => 'foo',
diff --git a/tests/ValidationTest.php b/tests/ValidationTest.php
index 3cad135..e866d42 100644
--- a/tests/ValidationTest.php
+++ b/tests/ValidationTest.php
@@ -29,7 +29,7 @@ public function testParseRule($rules, $expectedResult)
         $this->assertSame($expectedResult, $result);
     }
 
-    public function parseRuleProvider(): array
+    public static function parseRuleProvider(): array
     {
         return [
             [