diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index a668078..fc6cd7a 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -33,10 +33,10 @@ jobs:
       run: composer install --prefer-dist --no-progress
 
     - name: Run CS
-      run: vendor/bin/phpcs -p --extensions=php ./src ./tests
+      run: vendor/bin/phpcs
 
     - name: Run stan
-      run: vendor/bin/phpstan analyse ./src --level 4
+      run: vendor/bin/phpstan analyse
 
     - name: Run tests
       run: vendor/bin/phpunit --coverage-clover=coverage.xml
diff --git a/.gitignore b/.gitignore
index 98aab43..a192a98 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@
 /nbproject
 /phpunit.xml
 /coverage.xml
+.phpunit.*
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 0b92138..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,44 +0,0 @@
-language: php
-
-dist: trusty
-
-sudo: false
-
-php:
-  - 5.6
-  - 7.0
-  - 7.1
-  
-env:
-  global:
-    - DEFAULT=1
-
-matrix:
-  fast_finish: true
-
-  include:
-    - php: 5.6
-      env: PHPCS=1 DEFAULT=0
-    - php: 7.1
-      env: PHPSTAN=4 DEFAULT=0
-    - php: 7.1
-      env: PHPSTAN=7 DEFAULT=0
-      
-  allow_failures:
-    - env: PHPCS=1 DEFAULT=0
-    - env: PHPSTAN=7 DEFAULT=0
-
-before_script:
-  - composer install;
-  - if [[ $PHPSTAN > 0 ]]; then composer require phpstan/phpstan:^0.7; fi
-
-script:
-  - if [[ $DEFAULT = 1 ]]; then vendor/bin/phpunit --coverage-clover=coverage.xml; fi
-  - if [[ $PHPCS = 1 ]]; then vendor/bin/phpcs -p --extensions=php ./src ./tests; fi
-  - if [[ $PHPSTAN > 0 ]]; then vendor/bin/phpstan analyse ./src --level $PHPSTAN; fi
-
-notifications:
-  email: false
-
-after_success:
-    - bash <(curl -s https://codecov.io/bash)
diff --git a/composer.json b/composer.json
index 457a990..fbbc832 100644
--- a/composer.json
+++ b/composer.json
@@ -5,13 +5,13 @@
 	"type": "cakephp-plugin",
 	"license": "MIT",
 	"require": {
-		"php": ">=5.6",
-		"cakephp/orm": "^3.4"
+		"cakephp/orm": "~4.0"
 	},
 	"require-dev": {
-		"cakephp/cakephp": "~3.4.0",
-		"cakephp/cakephp-codesniffer": "^3.0",
-		"phpunit/phpunit": "^5.6|^6"
+		"cakephp/cakephp": "~4.0",
+		"cakephp/cakephp-codesniffer": "^4.0",
+		"phpunit/phpunit": "^9.5",
+		"phpstan/phpstan": "^2.0"
 	},
 	"autoload": {
 		"psr-4": {
@@ -23,5 +23,10 @@
 			"Cake\\Test\\": "vendor/cakephp/cakephp/tests",
 			"Robotusers\\Chunk\\Test\\": "tests"
 		}
+	},
+	"config": {
+		"allow-plugins": {
+			"dealerdirect/phpcodesniffer-composer-installer": true
+		}
 	}
 }
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 36805de..d09769c 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -1,4 +1,16 @@
 <?xml version="1.0"?>
-<ruleset name="CakePHP Core">
- <rule ref="./vendor/cakephp/cakephp-codesniffer/CakePHP/ruleset.xml"/>
+<ruleset name="Robotusers">
+    <rule ref="CakePHP">
+        <exclude name="CakePHP.Commenting.FunctionComment.Missing"/>
+        <exclude name="CakePHP.Commenting.FunctionComment.MissingParamComment"/>
+        <exclude name="CakePHP.Commenting.FunctionComment.MissingParamTag"/>
+        <exclude name="CakePHP.NamingConventions.ValidTraitName"/>
+        <exclude name="SlevomatCodingStandard.TypeHints.PropertyTypeHint"/>
+        <exclude name="SlevomatCodingStandard.TypeHints.ReturnTypeHint"/>
+        <exclude name="SlevomatCodingStandard.TypeHints.ParameterTypeHint"/>
+        <exclude name="SlevomatCodingStandard.TypeHints.NullableTypeForNullDefaultValue"/>        
+        <exclude name="Generic.Files.LineLength"/>
+    </rule>
+    <file>src/</file> 
+    <file>tests/</file> 
 </ruleset>
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..86901ed
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,7 @@
+parameters:
+    level: 4
+#    reportUnmatchedIgnoredErrors: false
+#    treatPhpDocTypesAsCertain: false
+    paths:
+        - src/ 
+        - tests/ 
\ No newline at end of file
diff --git a/src/Model/Behavior/ChunkBehavior.php b/src/Model/Behavior/ChunkBehavior.php
index 2ad8d19..1c046c6 100644
--- a/src/Model/Behavior/ChunkBehavior.php
+++ b/src/Model/Behavior/ChunkBehavior.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 /*
  * The MIT License
  *
@@ -30,13 +32,12 @@
 
 class ChunkBehavior extends Behavior
 {
-
     /**
      * Returns chunked result set.
      *
-     * @param Query $query Query instance.
+     * @param \Cake\ORM\Query $query Query instance.
      * @param array $config Config.
-     * @return ResultSet
+     * @return \Robotusers\Chunk\ORM\ResultSet
      */
     public function chunk(Query $query, array $config = [])
     {
diff --git a/src/ORM/ResultSet.php b/src/ORM/ResultSet.php
index 94cab36..9cb031a 100644
--- a/src/ORM/ResultSet.php
+++ b/src/ORM/ResultSet.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 /*
  * The MIT License
  *
@@ -45,7 +47,7 @@ class ResultSet implements ResultSetInterface
     /**
      * Query instance.
      *
-     * @var Query
+     * @var \Cake\ORM\Query
      */
     protected $query;
 
@@ -113,15 +115,15 @@ class ResultSet implements ResultSetInterface
      * @var array
      */
     protected $_defaultConfig = [
-        'size' => 1000
+        'size' => 1000,
     ];
 
     /**
      * Constructor.
      *
-     * @param Query $query Query object.
+     * @param \Cake\ORM\Query $query Query object.
      * @param array $config Configuration.
-     * @throws RuntimeException When query is not supported.
+     * @throws \RuntimeException When query is not supported.
      */
     public function __construct(Query $query, array $config = [])
     {
@@ -140,34 +142,36 @@ public function __construct(Query $query, array $config = [])
     }
 
     /**
-     * {@inheritDoc}
+     * @inheritDoc
      */
+    #[\ReturnTypeWillChange]
     public function current()
     {
         return $this->current;
     }
 
     /**
-     * {@inheritDoc}
+     * @inheritDoc
      */
+    #[\ReturnTypeWillChange]
     public function key()
     {
         return $this->index;
     }
 
     /**
-     * {@inheritDoc}
+     * @inheritDoc
      */
-    public function next()
+    public function next(): void
     {
         $this->index++;
         $this->chunkIndex++;
     }
 
     /**
-     * {@inheritDoc}
+     * @inheritDoc
      */
-    public function rewind()
+    public function rewind(): void
     {
         $this->index = 0;
         $this->page = 1;
@@ -176,9 +180,9 @@ public function rewind()
     }
 
     /**
-     * {@inheritDoc}
+     * @inheritDoc
      */
-    public function valid()
+    public function valid(): bool
     {
         if ($this->limit && $this->index >= $this->limit) {
             return false;
@@ -235,30 +239,40 @@ protected function fetchChunk()
     }
 
     /**
-     * {@inheritDoc}
+     * @inheritDoc
      */
-    public function count()
+    public function count(): int
     {
         throw new RuntimeException('Count is not supported yet.');
     }
 
     /**
-     * Serialization is not supported (yet).
-     *
      * {@inheritDoc}
+     *
+     * Serialization is not supported (yet).     *
      */
     public function serialize()
     {
         throw new RuntimeException('You cannot serialize this result set.');
     }
 
+    public function __serialize(): array
+    {
+        throw new RuntimeException('You cannot serialize this result set.');
+    }
+
     /**
-     * Serialization is not supported (yet).
-     *
      * {@inheritDoc}
+     *
+     * Serialization is not supported (yet).     *
      */
     public function unserialize($serialized)
     {
         throw new RuntimeException('You cannot unserialize this result set.');
     }
+
+    public function __unserialize(array $data): void
+    {
+        throw new RuntimeException('You cannot unserialize this result set.');
+    }
 }
diff --git a/tests/TestCase/Model/Behavior/ChunkBehaviorTest.php b/tests/TestCase/Model/Behavior/ChunkBehaviorTest.php
index 88f5bb9..3cde097 100644
--- a/tests/TestCase/Model/Behavior/ChunkBehaviorTest.php
+++ b/tests/TestCase/Model/Behavior/ChunkBehaviorTest.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 /*
  * The MIT License
  *
@@ -37,7 +39,7 @@
 class ChunkBehaviorTest extends TestCase
 {
     public $fixtures = [
-        'core.authors'
+        'core.Authors',
     ];
 
     public function testChunk()
@@ -47,7 +49,7 @@ public function testChunk()
 
         $behavior = new ChunkBehavior($table);
         $chunk = $behavior->chunk($query, [
-            'size' => 100
+            'size' => 100,
         ]);
 
         $this->assertInstanceOf(ResultSet::class, $chunk);
diff --git a/tests/TestCase/ORM/ResultSetTest.php b/tests/TestCase/ORM/ResultSetTest.php
index b71d920..574a7f9 100644
--- a/tests/TestCase/ORM/ResultSetTest.php
+++ b/tests/TestCase/ORM/ResultSetTest.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 /*
  * The MIT License
  *
@@ -28,16 +30,17 @@
 use Cake\ORM\TableRegistry;
 use Cake\TestSuite\TestCase;
 use Robotusers\Chunk\ORM\ResultSet;
+use RuntimeException;
 
 /**
  * Description of ResultsSetTest
  *
  * @author Robert Pustułka <r.pustulka@robotusers.com>
  */
-class ResultsSetTest extends TestCase
+class ResultSetTest extends TestCase
 {
     public $fixtures = [
-        'core.authors'
+        'core.Authors',
     ];
 
     public function testSameResults()
@@ -48,7 +51,7 @@ public function testSameResults()
 
         $standardResults = $query->all();
         $chunkedResults = new ResultSet($query, [
-            'size' => 1
+            'size' => 1,
         ]);
 
         $this->assertEquals($standardResults->toArray(), $chunkedResults->toArray());
@@ -66,7 +69,7 @@ public function testMultipleQueriesFired()
         });
 
         $results = new ResultSet($query, [
-            'size' => 1
+            'size' => 1,
         ]);
 
         $results->toList();
@@ -82,18 +85,17 @@ public function testLimitAndOffset()
 
         $standardResults = $query->all();
         $chunkedResults = new ResultSet($query, [
-            'size' => 1
+            'size' => 1,
         ]);
 
         $this->assertEquals($standardResults->toArray(), $chunkedResults->toArray());
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage You cannot serialize this result set.
-     */
     public function testSerialize()
     {
+        $this->expectException(RuntimeException::class);
+        $this->expectErrorMessage('You cannot serialize this result set.');
+
         $table = TableRegistry::get('Authors');
         $query = $table->find();
 
@@ -101,12 +103,11 @@ public function testSerialize()
         $chunkedResults->serialize();
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage You cannot unserialize this result set.
-     */
     public function testUnserialize()
     {
+        $this->expectException(RuntimeException::class);
+        $this->expectErrorMessage('You cannot unserialize this result set.');
+
         $table = TableRegistry::get('Authors');
         $query = $table->find();
 
@@ -114,12 +115,11 @@ public function testUnserialize()
         $chunkedResults->unserialize('');
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage Count is not supported yet.
-     */
     public function testCount()
     {
+        $this->expectException(RuntimeException::class);
+        $this->expectErrorMessage('Count is not supported yet.');
+
         $table = TableRegistry::get('Authors');
         $query = $table->find();
 
@@ -127,12 +127,11 @@ public function testCount()
         $chunkedResults->count();
     }
 
-    /**
-     * @expectedException RuntimeException
-     * @expectedExceptionMessage You cannot chunk a non-select query.
-     */
     public function testInvalidQuery()
     {
+        $this->expectException(RuntimeException::class);
+        $this->expectErrorMessage('You cannot chunk a non-select query.');
+
         $table = TableRegistry::get('Authors');
         $query = $table->query()->insert(['foo' => 'bar']);
 
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 1c2790c..eac92ad 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 /**
  * Test suite bootstrap.
  *
@@ -6,8 +8,12 @@
  * has been installed as a dependency of the plugin, or the plugin is itself
  * installed as a dependency of an application.
  */
+
+use Cake\Core\BasePlugin;
 use Cake\Core\Plugin;
 
+error_reporting(E_ALL & ~E_USER_DEPRECATED);
+
 $findRoot = function ($root) {
     do {
         $lastRoot = $root;
@@ -17,7 +23,7 @@
         }
     } while ($root !== $lastRoot);
 
-    throw new Exception("Cannot find the root of the application, unable to run tests");
+    throw new Exception('Cannot find the root of the application, unable to run tests');
 };
 $root = $findRoot(__FILE__);
 unset($findRoot);
@@ -31,6 +37,7 @@
 
 require $root . '/vendor/cakephp/cakephp/tests/bootstrap.php';
 
-Plugin::load('Robotusers/Chunk', [
-    'path' => PLUGIN_ROOT . DS
-]);
+Plugin::getCollection()->add(new BasePlugin([
+    'name' => 'Robotusers/Chunk',
+    'path' => PLUGIN_ROOT . DS,
+]));