diff --git a/.editorconfig b/.editorconfig
index a84f86c..de2fe7e 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -6,13 +6,11 @@ root = true
 [*]
 indent_style = space
 indent_size = 4
+charset = "utf-8"
 end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
 
-[*.bat]
-end_of_line = crlf
-
 [*.yml]
 indent_style = space
-indent_size = 2
\ No newline at end of file
+indent_size = 2
diff --git a/.gitattributes b/.gitattributes
index 17493ec..d912dbb 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,8 +1,11 @@
 # Remove files for archives generated using `git archive`
+CONTRIBUTING.md export-ignore
 .editorconfig export-ignore
 .gitattributes export-ignore
 .gitignore export-ignore
-.semver export-ignore
 phpunit.xml.dist export-ignore
 .travis.yml export-ignore
+.scrutinizer.yml export-ignore
 tests export-ignore
+docs export-ignore
+.github export-ignore
diff --git a/.gitignore b/.gitignore
index 364f9bd..5209c91 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,7 @@
-/composer.lock
-/plugins
-/vendor
+*.pyc
+docs/_build
+phpunit.xml
+vendor/
+composer.lock
+tmp
+.phpunit.result.cache
diff --git a/.semver b/.semver
deleted file mode 100644
index 3581f63..0000000
--- a/.semver
+++ /dev/null
@@ -1,6 +0,0 @@
----
-:major: 0
-:minor: 0
-:patch: 0
-:special: ''
-:metadata: ''
diff --git a/.sticker.yml b/.sticker.yml
new file mode 100644
index 0000000..08993b0
--- /dev/null
+++ b/.sticker.yml
@@ -0,0 +1,11 @@
+linters:
+  phpcs:
+    standard: CakePHP4
+    extensions: 'php'
+    fixer: true
+files:
+  ignore:
+    - 'vendor/*'
+fixers:
+  enable: true
+  workflow: commit
diff --git a/.travis.yml b/.travis.yml
index 9c729f2..af10731 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,52 +1,65 @@
 language: php
 
 php:
-  - 5.6
   - 7.2
   - 7.3
-
-services:
-  - mysql
-  - postgresql
+  - 7.4
 
 env:
   matrix:
-    - DB=sqlite db_dsn='sqlite:///:memory:'
-    - DB=mysql db_dsn='mysql://root@127.0.0.1/cakephp_test?init[]=SET sql_mode = "STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"'
+    - DB=mysql db_dsn='mysql://root@127.0.0.1/cakephp_test'
     - DB=pgsql db_dsn='postgres://postgres@127.0.0.1/cakephp_test'
+    - DB=sqlite db_dsn='sqlite:///:memory:'
 
   global:
     - DEFAULT=1
 
+services:
+  - mysql
+  - postgresql
+
 matrix:
   fast_finish: true
 
   include:
-    - php: 7.3
+    - php: 7.2
       env: PHPCS=1 DEFAULT=0
 
-    - php: 5.6
-      env: PREFER_LOWEST=1
+    - php: 7.2
+      env: STATIC_ANALYSIS=1 DEFAULT=0
 
 before_script:
   - if [[ $TRAVIS_PHP_VERSION != 7.2 ]]; then phpenv config-rm xdebug.ini; fi
 
-  - if [[ $PREFER_LOWEST != 1 ]]; then composer install --no-interaction; fi
+  - if [[ $PREFER_LOWEST != 1 ]]; then composer update --no-interaction; fi
   - if [[ $PREFER_LOWEST == 1 ]]; then composer update --no-interaction --prefer-lowest --prefer-stable; fi
 
-  - if [[ $DB == 'mysql' ]]; then mysql -e 'CREATE DATABASE cakephp_test;'; fi
-  - if [[ $DB == 'pgsql' ]]; then psql -c 'CREATE DATABASE cakephp_test;' -U postgres; fi
+  - if [[ $DB = 'mysql' ]]; then mysql -u root -e 'CREATE DATABASE cakephp_test;'; fi
+  - if [[ $DB = 'pgsql' ]]; then psql -c 'CREATE DATABASE cakephp_test;' -U postgres; fi
 
-  - if [[ $PHPCS == '1' ]]; then composer require cakephp/cakephp-codesniffer:^3.0; fi
+  - if [[ $PHPCS = 1 ]]; then composer require cakephp/cakephp-codesniffer:^4.0; fi
+  - if [[ $STATIC_ANALYSIS = 1 ]]; then composer require --dev phpstan/phpstan:^0.12 psalm/phar:^3.7; fi
 
 script:
-  - if [[ $DEFAULT == 1 && $TRAVIS_PHP_VERSION == 7.2 ]]; then vendor/bin/phpunit --coverage-clover=clover.xml; fi
-  - if [[ $DEFAULT == 1 && $TRAVIS_PHP_VERSION != 7.2 ]]; then vendor/bin/phpunit; fi
+  - |
+      if [[ $DEFAULT = 1 && $TRAVIS_PHP_VERSION = 7.2 ]]; then
+        mkdir -p build/logs
+        vendor/bin/phpunit --coverage-clover=build/logs/clover.xml
+      fi
+
+  - if [[ $DEFAULT = 1 && $TRAVIS_PHP_VERSION != 7.2 ]]; then vendor/bin/phpunit; fi
+
+  - if [[ $PHPCS = 1 ]]; then vendor/bin/phpcs -p --standard=vendor/cakephp/cakephp-codesniffer/CakePHP ./src ./tests; fi
 
-  - if [[ $PHPCS == 1 ]]; then vendor/bin/phpcs -p --extensions=php --standard=vendor/cakephp/cakephp-codesniffer/CakePHP ./src ./tests; fi
+  - if [[ $STATIC_ANALYSIS = 1 ]]; then vendor/bin/phpstan.phar analyse src && vendor/bin/psalm.phar --show-info=false; fi
 
 after_success:
-  - if [[ $DEFAULT == 1 && $TRAVIS_PHP_VERSION == 7.2 ]]; then bash <(curl -s https://codecov.io/bash); fi
+  - |
+      if [[ $DEFAULT = 1 && $TRAVIS_PHP_VERSION = 7.2 ]]; then
+        wget https://github.com/php-coveralls/php-coveralls/releases/download/v2.1.0/php-coveralls.phar
+        chmod +x php-coveralls.phar
+        ./php-coveralls.phar
+      fi
 
 notifications:
   email: false
diff --git a/README.md b/README.md
index bc73b1d..f965c16 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,12 @@ Load the plugin by either running this console command:
 bin/cake plugin load Muffin/Obfuscate
 ```
 
+or by manually adding the following line to `src/Application.php`:
+
+```php
+$this->addPlugin('Muffin/Obfuscate');
+```
+
 Lastly, composer install (any combination of) the obfuscation libraries you
 want to use in your application:
 
diff --git a/VERSION b/VERSION
deleted file mode 100644
index ae39fab..0000000
--- a/VERSION
+++ /dev/null
@@ -1 +0,0 @@
-v0.0.0
diff --git a/composer.json b/composer.json
index 5b9dd03..3656285 100644
--- a/composer.json
+++ b/composer.json
@@ -31,11 +31,14 @@
         "source": "https://github.com/usemuffin/obfuscate"
     },
     "require": {
-        "cakephp/orm": "^3.5"
+        "cakephp/orm": "^4.0"
     },
     "require-dev": {
-        "cakephp/cakephp": "^3.5",
-        "phpunit/phpunit": "^5.7.14|^6.0",
+        "cakephp/cakephp": "^4.0",
+        "cakephp/cakephp-codesniffer": "^4.0",
+        "phpstan/phpstan": "^0.12",
+        "phpunit/phpunit": "~8.5.0",
+        "psalm/phar": "^3.9",
         "zackkitzmiller/tiny": "^1.2",
         "jenssegers/optimus": "^0.2",
         "hashids/hashids": "^1.0.5"
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
new file mode 100644
index 0000000..f51e71c
--- /dev/null
+++ b/phpstan-baseline.neon
@@ -0,0 +1,2 @@
+parameters:
+    ignoreErrors: []
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..ea3d1a8
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,7 @@
+includes:
+    - phpstan-baseline.neon
+
+parameters:
+    level: 6
+    checkGenericClassInNonGenericObjectType: false
+    checkMissingIterableValueType: false
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 813017e..56c0f03 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -3,6 +3,7 @@
     bootstrap="./tests/bootstrap.php"
     colors="true"
     stopOnFailure="false"
+    convertDeprecationsToExceptions="false"
     >
 
     <testsuites>
diff --git a/psalm.xml b/psalm.xml
new file mode 100644
index 0000000..15a7cd6
--- /dev/null
+++ b/psalm.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0"?>
+<psalm
+    totallyTyped="false"
+    resolveFromConfigFile="true"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd">
+    <projectFiles>
+        <directory name="src" />
+        <ignoreFiles>
+            <directory name="vendor" />
+        </ignoreFiles>
+    </projectFiles>
+
+    <issueHandlers>
+        <MissingClosureReturnType errorLevel="info" />
+
+        <PropertyNotSetInConstructor errorLevel="info" />
+        <MissingConstructor errorLevel="info" />
+        <MissingClosureParamType errorLevel="info" />
+
+        <DocblockTypeContradiction errorLevel="info" />
+        <RedundantConditionGivenDocblockType errorLevel="info" />
+
+        <UndefinedPropertyFetch errorLevel="info" />
+        <UndefinedThisPropertyFetch errorLevel="info" />
+        <UndefinedPropertyAssignment errorLevel="info" />
+    </issueHandlers>
+</psalm>
diff --git a/src/Model/Behavior/ObfuscateBehavior.php b/src/Model/Behavior/ObfuscateBehavior.php
index dde0a92..bc4ff04 100644
--- a/src/Model/Behavior/ObfuscateBehavior.php
+++ b/src/Model/Behavior/ObfuscateBehavior.php
@@ -1,14 +1,17 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Model\Behavior;
 
 use ArrayObject;
 use Cake\Core\Exception\Exception;
+use Cake\Database\Expression\Comparison;
 use Cake\Datasource\EntityInterface;
-use Cake\Event\Event;
+use Cake\Event\EventInterface;
 use Cake\ORM\Behavior;
 use Cake\ORM\Query;
-use Cake\ORM\ResultSet;
 use Muffin\Obfuscate\Model\Behavior\Strategy\StrategyInterface;
+use RuntimeException;
 
 /**
  * Class ObfuscateBehavior
@@ -16,7 +19,6 @@
  */
 class ObfuscateBehavior extends Behavior
 {
-
     /**
      * {@inheritdoc}
      */
@@ -38,7 +40,7 @@ class ObfuscateBehavior extends Behavior
      * @param array $config Behavior's configuration.
      * @return void
      */
-    public function initialize(array $config)
+    public function initialize(array $config): void
     {
         $this->verifyConfig();
     }
@@ -48,10 +50,10 @@ public function initialize(array $config)
      *
      * @return void
      */
-    public function verifyConfig()
+    public function verifyConfig(): void
     {
         $strategy = $this->getConfig('strategy');
-        if (!$strategy) {
+        if (empty($strategy)) {
             throw new Exception('Missing required obfuscation strategy.');
         }
 
@@ -67,14 +69,17 @@ public function verifyConfig()
     /**
      * Callback to obfuscate the record(s)' primary key returned after a save operation.
      *
-     * @param \Cake\ORM\Behavior\Event $event Event.
-     * @param \Cake\ORM\Behavior\EntityInterface $entity Entity.
+     * @param \Cake\Event\EventInterface $event EventInterface.
+     * @param \Cake\Datasource\EntityInterface $entity Entity.
      * @param \ArrayObject $options Options.
      * @return void
      */
-    public function afterSave(Event $event, EntityInterface $entity, ArrayObject $options)
+    public function afterSave(EventInterface $event, EntityInterface $entity, ArrayObject $options)
     {
         $pk = $this->_table->getPrimaryKey();
+        if (is_array($pk)) {
+            throw new RuntimeException('Composite primary keys are not supported.');
+        }
         $entity->set($pk, $this->obfuscate($entity->{$pk}));
         $entity->setDirty($pk, false);
     }
@@ -82,13 +87,13 @@ public function afterSave(Event $event, EntityInterface $entity, ArrayObject $op
     /**
      * Callback to set the `obfuscated` finder on all associations.
      *
-     * @param \Cake\ORM\Behavior\Event $event Event.
+     * @param \Cake\Event\EventInterface $event EventInterface.
      * @param \Cake\ORM\Query $query Query.
      * @param \ArrayObject $options Options.
      * @param bool $primary True if this is the primary table.
      * @return void
      */
-    public function beforeFind(Event $event, Query $query, ArrayObject $options, $primary)
+    public function beforeFind(EventInterface $event, Query $query, ArrayObject $options, $primary)
     {
         if (empty($options['obfuscate']) || !$primary) {
             return;
@@ -96,8 +101,12 @@ public function beforeFind(Event $event, Query $query, ArrayObject $options, $pr
 
         $query->traverseExpressions(function ($expression) {
             $pk = $this->_table->getPrimaryKey();
+            if (is_array($pk)) {
+                throw new RuntimeException('Composite primary keys are not supported.');
+            }
+
             if (
-                method_exists($expression, 'getField')
+                $expression instanceof Comparison
                 && in_array($expression->getField(), [$pk, $this->_table->aliasField($pk)])
             ) {
                 $expression->setValue($this->elucidate($expression->getValue()));
@@ -173,7 +182,7 @@ public function elucidate($str)
     /**
      * Get the configured strategy.
      *
-     * @return \Muffin\Obfuscate\Model\Behavior\ObfuscateStrategy\StrategyInterface
+     * @return \Muffin\Obfuscate\Model\Behavior\Strategy\StrategyInterface
      */
     public function strategy()
     {
diff --git a/src/Model/Behavior/Strategy/HashidStrategy.php b/src/Model/Behavior/Strategy/HashidStrategy.php
index af9980c..145c5a5 100644
--- a/src/Model/Behavior/Strategy/HashidStrategy.php
+++ b/src/Model/Behavior/Strategy/HashidStrategy.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Model\Behavior\Strategy;
 
 use Cake\Core\Configure;
@@ -10,30 +12,12 @@
  */
 class HashidStrategy implements StrategyInterface
 {
-
-    protected $_hashid;
-
     /**
-     * Random alpha-numeric set where each character must only be
-     * used exactly once.
+     * Obfuscator.
      *
-     * @var string
+     * @var \Hashids\Hashids
      */
-    protected $_salt;
-
-    /**
-     * The minimum hash length.
-     *
-     * @var int
-     */
-    protected $_minLength;
-
-    /**
-     * Custom alphabet to use.
-     *
-     * @var string
-     */
-    protected $_alphabet;
+    protected $_hashid;
 
     /**
      * Constructor.
@@ -51,9 +35,6 @@ public function __construct($salt = null, $minLength = 0, $alphabet = null)
         if (empty($salt)) {
             throw new \Exception('Missing salt for Hashid strategy');
         }
-        $this->_salt = $salt;
-        $this->_minLength = $minLength;
-        $this->_alphabet = $alphabet;
 
         if ($alphabet === null) {
             $this->_hashid = new Hashids($salt, $minLength);
@@ -65,12 +46,12 @@ public function __construct($salt = null, $minLength = 0, $alphabet = null)
     /**
      * {@inheritdoc}
      *
-     * @param string $str String to obfuscate.
+     * @param int|string $str String to obfuscate.
      * @return string
      */
     public function obfuscate($str)
     {
-        return $this->_hashid->encode($str);
+        return $this->_hashid->encode((string)$str);
     }
 
     /**
diff --git a/src/Model/Behavior/Strategy/OptimusStrategy.php b/src/Model/Behavior/Strategy/OptimusStrategy.php
index 9258455..595eb9e 100644
--- a/src/Model/Behavior/Strategy/OptimusStrategy.php
+++ b/src/Model/Behavior/Strategy/OptimusStrategy.php
@@ -1,10 +1,18 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Model\Behavior\Strategy;
 
+use InvalidArgumentException;
 use Jenssegers\Optimus\Optimus;
 
 class OptimusStrategy implements StrategyInterface
 {
+    /**
+     * Obfuscator.
+     *
+     * @var \Jenssegers\Optimus\Optimus
+     */
     protected $_optimus;
 
     /**
@@ -22,22 +30,30 @@ public function __construct($prime, $inverse, $random)
     /**
      * {@inheritdoc}
      *
-     * @param string $str String to obfuscate.
-     * @return int
+     * @param int|string $str String to obfuscate.
+     * @return string
      */
     public function obfuscate($str)
     {
-        return $this->_optimus->encode($str);
+        if (!is_numeric($str)) {
+            throw new InvalidArgumentException('Argument should be an integer');
+        }
+
+        return (string)$this->_optimus->encode((int)$str);
     }
 
     /**
      * {@inheritdoc}
      *
      * @param string $str String to elucidate.
-     * @return int
+     * @return string
      */
     public function elucidate($str)
     {
-        return $this->_optimus->decode($str);
+        if (!is_numeric($str)) {
+            throw new InvalidArgumentException('Argument should be an integer');
+        }
+
+        return (string)$this->_optimus->decode((int)$str);
     }
 }
diff --git a/src/Model/Behavior/Strategy/StrategyInterface.php b/src/Model/Behavior/Strategy/StrategyInterface.php
index 431d1ba..c5770b3 100644
--- a/src/Model/Behavior/Strategy/StrategyInterface.php
+++ b/src/Model/Behavior/Strategy/StrategyInterface.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Model\Behavior\Strategy;
 
 /**
@@ -7,11 +9,10 @@
  */
 interface StrategyInterface
 {
-
     /**
-     * Obfuscates a given string.
+     * Obfuscates a given integer.
      *
-     * @param string $str String to obfuscate.
+     * @param int|string $str String to obfuscate.
      * @return string
      */
     public function obfuscate($str);
diff --git a/src/Model/Behavior/Strategy/TinyStrategy.php b/src/Model/Behavior/Strategy/TinyStrategy.php
index 2e06bd7..43e7b93 100644
--- a/src/Model/Behavior/Strategy/TinyStrategy.php
+++ b/src/Model/Behavior/Strategy/TinyStrategy.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Model\Behavior\Strategy;
 
 use ZackKitzmiller\Tiny;
@@ -9,7 +11,6 @@
  */
 class TinyStrategy implements StrategyInterface
 {
-
     /**
      * Random alpha-numeric set where each character must only be
      * used exactly once.
@@ -39,12 +40,12 @@ public function __construct($set)
     /**
      * {@inheritdoc}
      *
-     * @param string $str String to obfuscate.
+     * @param int|string $str String to obfuscate.
      * @return string
      */
     public function obfuscate($str)
     {
-        return $this->_tiny->to($str);
+        return $this->_tiny->to((string)$str);
     }
 
     /**
diff --git a/src/Plugin.php b/src/Plugin.php
new file mode 100644
index 0000000..04692cd
--- /dev/null
+++ b/src/Plugin.php
@@ -0,0 +1,19 @@
+<?php
+declare(strict_types=1);
+
+namespace Muffin\Obfuscate;
+
+use Cake\Core\BasePlugin;
+
+/**
+ * Plugin class for obfuscate
+ */
+class Plugin extends BasePlugin
+{
+    /**
+     * Plugin name.
+     *
+     * @var string
+     */
+    protected $name = 'Obfuscate';
+}
diff --git a/tests/Fixture/ArticlesFixture.php b/tests/Fixture/ArticlesFixture.php
index a07b002..a0f2cd5 100644
--- a/tests/Fixture/ArticlesFixture.php
+++ b/tests/Fixture/ArticlesFixture.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\Fixture;
 
 use Cake\TestSuite\Fixture\TestFixture;
@@ -31,7 +33,7 @@ class ArticlesFixture extends TestFixture
         ['author_id' => 2, 'title' => 'Second Article'],
     ];
 
-    public function init()
+    public function init(): void
     {
         $created = $modified = date('Y-m-d H:i:s');
         array_walk($this->records, function (&$record) use ($created, $modified) {
diff --git a/tests/Fixture/ArticlesTagsFixture.php b/tests/Fixture/ArticlesTagsFixture.php
index 2bbe140..62b94d2 100644
--- a/tests/Fixture/ArticlesTagsFixture.php
+++ b/tests/Fixture/ArticlesTagsFixture.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\Fixture;
 
 use Cake\TestSuite\Fixture\TestFixture;
diff --git a/tests/Fixture/AuthorsFixture.php b/tests/Fixture/AuthorsFixture.php
index f9c9fdd..16cecd8 100644
--- a/tests/Fixture/AuthorsFixture.php
+++ b/tests/Fixture/AuthorsFixture.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\Fixture;
 
 use Cake\TestSuite\Fixture\TestFixture;
@@ -30,7 +32,7 @@ class AuthorsFixture extends TestFixture
         ['name' => 'Jane'],
     ];
 
-    public function init()
+    public function init(): void
     {
         $created = $modified = date('Y-m-d H:i:s');
         array_walk($this->records, function (&$record) use ($created, $modified) {
diff --git a/tests/Fixture/CommentsFixture.php b/tests/Fixture/CommentsFixture.php
index 8c3842b..2c35c94 100644
--- a/tests/Fixture/CommentsFixture.php
+++ b/tests/Fixture/CommentsFixture.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\Fixture;
 
 use Cake\TestSuite\Fixture\TestFixture;
@@ -31,7 +33,7 @@ class CommentsFixture extends TestFixture
         ['obfuscate_article_id' => 1, 'title' => 'Hello Universe'],
     ];
 
-    public function init()
+    public function init(): void
     {
         $created = $modified = date('Y-m-d H:i:s');
         array_walk($this->records, function (&$record) use ($created, $modified) {
diff --git a/tests/Fixture/TagsFixture.php b/tests/Fixture/TagsFixture.php
index 69ac6e8..d4f5a25 100644
--- a/tests/Fixture/TagsFixture.php
+++ b/tests/Fixture/TagsFixture.php
@@ -1,4 +1,6 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\Fixture;
 
 use Cake\TestSuite\Fixture\TestFixture;
@@ -30,7 +32,7 @@ class TagsFixture extends TestFixture
         ['name' => 'Bar'],
     ];
 
-    public function init()
+    public function init(): void
     {
         $created = $modified = date('Y-m-d H:i:s');
         array_walk($this->records, function (&$record) use ($created, $modified) {
diff --git a/tests/TestCase/Model/Behavior/ObfuscateBehaviorTest.php b/tests/TestCase/Model/Behavior/ObfuscateBehaviorTest.php
index 758b7e4..7fd7e1b 100644
--- a/tests/TestCase/Model/Behavior/ObfuscateBehaviorTest.php
+++ b/tests/TestCase/Model/Behavior/ObfuscateBehaviorTest.php
@@ -1,6 +1,9 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\TestCase\Model\Behavior;
 
+use Cake\Core\Exception\Exception;
 use Cake\ORM\Entity;
 use Cake\ORM\TableRegistry;
 use Cake\TestSuite\TestCase;
@@ -12,8 +15,20 @@ class ObfuscateBehaviorTest extends TestCase
      * @var \Cake\ORM\Table;
      */
     public $Articles;
+
+    /**
+     * @var \Cake\ORM\Table;
+     */
     public $Authors;
+
+    /**
+     * @var \Cake\ORM\Table;
+     */
     public $Comments;
+
+    /**
+     * @var \Cake\ORM\Table;
+     */
     public $Tags;
 
     /**
@@ -29,7 +44,7 @@ class ObfuscateBehaviorTest extends TestCase
         'plugin.Muffin/Obfuscate.ArticlesTags',
     ];
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
@@ -53,25 +68,25 @@ public function setUp()
             'through' => TableRegistry::get('Muffin/Obfuscate.ArticlesTags', ['table' => 'obfuscate_articles_tags']),
         ]);
 
-        $this->Obfuscate = $this->Articles->behaviors()->Obfuscate;
+        $this->Obfuscate = $this->Articles->getBehavior('Obfuscate');
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         TableRegistry::clear();
     }
 
-    /**
-     * @expectedException \Cake\Core\Exception\Exception
-     */
-    public function testVerifyConfig()
+    public function testVerifyConfig(): void
     {
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Missing required obfuscation strategy');
+
         $this->Articles->removeBehavior('Obfuscate');
         $this->Articles->addBehavior('Muffin/Obfuscate.Obfuscate');
     }
 
-    public function testAfterSave()
+    public function testAfterSave(): void
     {
         $entity = new Entity(['id' => 5, 'title' => 'foo']);
         $this->Articles->save($entity);
@@ -83,7 +98,7 @@ public function testAfterSave()
      * Make sure primary keys in returned result set are obfuscated when using
      * the `obfuscate` custom finder.
      */
-    public function testFindObfuscate()
+    public function testFindObfuscate(): void
     {
         $result = $this->Articles->find('obfuscate')->contain([
             $this->Authors->getAlias(),
@@ -101,7 +116,7 @@ public function testFindObfuscate()
      * Make sure primary keys in the returned result set are NOT obfuscated
      * when using default find.
      */
-    public function testFindWithoutObfuscate()
+    public function testFindWithoutObfuscate(): void
     {
         $result = $this->Articles->find()->contain([
             $this->Authors->getAlias(),
@@ -119,7 +134,7 @@ public function testFindWithoutObfuscate()
      * Make sure we can search for records using obfuscated primary key when
      * using the `obfuscated` custom finder.
      */
-    public function testFindObfuscated()
+    public function testFindObfuscated(): void
     {
         $results = $this->Articles->find('obfuscated')
             ->where(['id' => 'S'])
@@ -131,7 +146,7 @@ public function testFindObfuscated()
      * Make sure we can search for records using non-obfuscated primary key
      * when using default find.
      */
-    public function testFindWithoutObfuscated()
+    public function testFindWithoutObfuscated(): void
     {
         $results = $this->Articles->find()
             ->where(['id' => '1'])
@@ -139,13 +154,13 @@ public function testFindWithoutObfuscated()
         $this->assertEquals('1', $results[0]['id']);
     }
 
-    public function testObfuscate()
+    public function testObfuscate(): void
     {
-        $this->assertEquals('S', $this->Articles->obfuscate(1));
+        $this->assertEquals('S', $this->Articles->behaviors()->call('obfuscate', [1]));
     }
 
-    public function testElucidate()
+    public function testElucidate(): void
     {
-        $this->assertEquals(1, $this->Articles->elucidate('S'));
+        $this->assertEquals(1, $this->Articles->behaviors()->call('elucidate', ['S']));
     }
 }
diff --git a/tests/TestCase/Model/Behavior/Strategy/HashidStrategyTest.php b/tests/TestCase/Model/Behavior/Strategy/HashidStrategyTest.php
index 0b2dd7f..8c2b8c1 100644
--- a/tests/TestCase/Model/Behavior/Strategy/HashidStrategyTest.php
+++ b/tests/TestCase/Model/Behavior/Strategy/HashidStrategyTest.php
@@ -1,46 +1,52 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\TestCase\Model\Behavior\Strategy;
 
-use Cake\TestSuite\TestCase;
+use Exception;
 use Muffin\Obfuscate\Model\Behavior\Strategy\HashidStrategy;
+use PHPUnit\Framework\TestCase;
 
 class HashidStrategyTest extends TestCase
 {
-    public function setUp()
+    /**
+     * @var \Muffin\Obfuscate\Model\Behavior\Strategy\HashidStrategy;
+     */
+    public $strategy;
+
+    public function setUp(): void
     {
         $this->strategy = new HashidStrategy('5SX0TEjkR1mLOw8Gvq2VyJxIFhgCAYidrclDWaM3so9bfzZpuUenKtP74QNH6B');
     }
 
-    public function testObfuscate()
+    public function testObfuscate(): void
     {
-        $result = $this->assertEquals('k8', $this->strategy->obfuscate(1));
+        $this->assertEquals('k8', $this->strategy->obfuscate(1));
     }
 
-    public function testElucidate()
+    public function testElucidate(): void
     {
         $this->assertEquals(1, $this->strategy->elucidate('k8'));
     }
 
-    public function testMinLength()
+    public function testMinLength(): void
     {
         $this->strategy = new HashidStrategy('5SX0TEjkR1mLOw8Gvq2VyJxIFhgCAYidrclDWaM3so9bfzZpuUenKtP74QNH6B', 10);
 
         $this->assertEquals('qxPAk8pnOV', $this->strategy->obfuscate(1));
     }
 
-    public function testCustomAlphabet()
+    public function testCustomAlphabet(): void
     {
         $this->strategy = new HashidStrategy('5SX0TEjkR1mLOw8Gvq2VyJxIFhgCAYidrclDWaM3so9bfzZpuUenKtP74QNH6B', 0, 'abcdefghijklmnopqrstuvwxyz');
 
         $this->assertEquals('vg', $this->strategy->obfuscate(1));
     }
 
-    /**
-     * @expectedException Exception
-     * @expectedExceptionMessage Missing salt for Hashid strategy
-     */
-    public function testSaltException()
+    public function testSaltException(): void
     {
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Missing salt for Hashid strategy');
         new HashidStrategy();
     }
 }
diff --git a/tests/TestCase/Model/Behavior/Strategy/OptimusStrategyTest.php b/tests/TestCase/Model/Behavior/Strategy/OptimusStrategyTest.php
index aba98ec..6e7ff21 100644
--- a/tests/TestCase/Model/Behavior/Strategy/OptimusStrategyTest.php
+++ b/tests/TestCase/Model/Behavior/Strategy/OptimusStrategyTest.php
@@ -1,23 +1,30 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\TestCase\Model\Behavior\Strategy;
 
-use Cake\TestSuite\TestCase;
 use Muffin\Obfuscate\Model\Behavior\Strategy\OptimusStrategy;
+use PHPUnit\Framework\TestCase;
 
 class OptimusStrategyTest extends TestCase
 {
-    public function setUp()
+    /**
+     * @var \Muffin\Obfuscate\Model\Behavior\Strategy\OptimusStrategy;
+     */
+    public $strategy;
+
+    public function setUp(): void
     {
         $this->strategy = new OptimusStrategy(2123809381, 1885413229, 146808189);
     }
 
-    public function testObfuscate()
+    public function testObfuscate(): void
     {
         $this->assertEquals(1985404696, $this->strategy->obfuscate(1));
     }
 
-    public function testElucidate()
+    public function testElucidate(): void
     {
-        $this->assertEquals(1, $this->strategy->elucidate(1985404696));
+        $this->assertEquals(1, $this->strategy->elucidate('1985404696'));
     }
 }
diff --git a/tests/TestCase/Model/Behavior/Strategy/TinyStrategyTest.php b/tests/TestCase/Model/Behavior/Strategy/TinyStrategyTest.php
index d539db8..11c4dd7 100644
--- a/tests/TestCase/Model/Behavior/Strategy/TinyStrategyTest.php
+++ b/tests/TestCase/Model/Behavior/Strategy/TinyStrategyTest.php
@@ -1,22 +1,29 @@
 <?php
+declare(strict_types=1);
+
 namespace Muffin\Obfuscate\Test\TestCase\Model\Behavior\Strategy;
 
-use Cake\TestSuite\TestCase;
 use Muffin\Obfuscate\Model\Behavior\Strategy\TinyStrategy;
+use PHPUnit\Framework\TestCase;
 
 class TinyStrategyTest extends TestCase
 {
-    public function setUp()
+    /**
+     * @var \Muffin\Obfuscate\Model\Behavior\Strategy\TinyStrategy;
+     */
+    public $strategy;
+
+    public function setUp(): void
     {
         $this->strategy = new TinyStrategy('5SX0TEjkR1mLOw8Gvq2VyJxIFhgCAYidrclDWaM3so9bfzZpuUenKtP74QNH6B');
     }
 
-    public function testObfuscate()
+    public function testObfuscate(): void
     {
         $this->assertEquals('S', $this->strategy->obfuscate(1));
     }
 
-    public function testElucidate()
+    public function testElucidate(): void
     {
         $this->assertEquals(1, $this->strategy->elucidate('S'));
     }
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index c6dc570..39f2a49 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -1,28 +1,90 @@
 <?php
-/**
- * Test suite bootstrap.
- *
- * This function is used to find the location of CakePHP whether CakePHP
- * has been installed as a dependency of the plugin, or the plugin is itself
- * installed as a dependency of an application.
- */
-$findRoot = function ($root) {
-    do {
-        $lastRoot = $root;
-        $root = dirname($root);
-        if (is_dir($root . '/vendor/cakephp/cakephp')) {
-            return $root;
-        }
-    } while ($root !== $lastRoot);
-
-    throw new Exception("Cannot find the root of the application, unable to run tests");
+
+use Cake\Core\Plugin;
+// @codingStandardsIgnoreFile
+
+$findRoot = function () {
+    $root = dirname(__DIR__);
+    if (is_dir($root . '/vendor/cakephp/cakephp')) {
+        return $root;
+    }
+
+    $root = dirname(dirname(__DIR__));
+    if (is_dir($root . '/vendor/cakephp/cakephp')) {
+        return $root;
+    }
+
+    $root = dirname(dirname(dirname(__DIR__)));
+    if (is_dir($root . '/vendor/cakephp/cakephp')) {
+        return $root;
+    }
 };
-$root = $findRoot(__FILE__);
-unset($findRoot);
 
-chdir($root);
-if (file_exists($root . '/config/bootstrap.php')) {
-    require $root . '/config/bootstrap.php';
+if (!defined('DS')) {
+    define('DS', DIRECTORY_SEPARATOR);
+}
+define('ROOT', $findRoot());
+define('APP_DIR', 'test_app');
+define('WEBROOT_DIR', 'webroot');
+define('APP', ROOT . '/tests/test_app/src/');
+define('CONFIG', ROOT . '/tests/test_app/config/');
+define('WWW_ROOT', ROOT . DS . WEBROOT_DIR . DS);
+define('TESTS', ROOT . DS . 'tests' . DS);
+define('TMP', ROOT . DS . 'tmp' . DS);
+define('LOGS', TMP . 'logs' . DS);
+define('CACHE', TMP . 'cache' . DS);
+define('CAKE_CORE_INCLUDE_PATH', ROOT . '/vendor/cakephp/cakephp');
+define('CORE_PATH', CAKE_CORE_INCLUDE_PATH . DS);
+define('CAKE', CORE_PATH . 'src' . DS);
+
+require ROOT . '/vendor/autoload.php';
+require CORE_PATH . 'config/bootstrap.php';
+
+Cake\Core\Configure::write('App', [
+    'namespace' => 'Muffin\Obfuscate\Test\App',
+    'encoding' => 'UTF-8',
+    'fullBaseUrl' => 'http://localhost'
+]);
+Cake\Core\Configure::write('debug', true);
+
+$TMP = new \Cake\Filesystem\Folder(TMP);
+$TMP->create(TMP . 'cache/models', 0777);
+$TMP->create(TMP . 'cache/persistent', 0777);
+$TMP->create(TMP . 'cache/views', 0777);
+
+$cache = [
+    'default' => [
+        'engine' => 'File'
+    ],
+    '_cake_core_' => [
+        'className' => 'File',
+        'prefix' => 'muffin_obfuscate_myapp_cake_core_',
+        'path' => CACHE . 'persistent/',
+        'serialize' => true,
+        'duration' => '+10 seconds'
+    ],
+    '_cake_model_' => [
+        'className' => 'File',
+        'prefix' => 'muffin_obfuscate_my_app_cake_model_',
+        'path' => CACHE . 'models/',
+        'serialize' => 'File',
+        'duration' => '+10 seconds'
+    ]
+];
+
+Cake\Cache\Cache::setConfig($cache);
+Cake\Core\Configure::write('Session', [
+    'defaults' => 'php'
+]);
+
+// Ensure default test connection is defined
+if (!getenv('db_dsn')) {
+    putenv('db_dsn=sqlite:///:memory:');
 }
 
-require $root . '/vendor/cakephp/cakephp/tests/bootstrap.php';
+Cake\Datasource\ConnectionManager::setConfig('test', [
+    'url' => getenv('db_dsn'),
+    'timezone' => 'UTC'
+]);
+
+Plugin::getCollection()->add(new \Muffin\Obfuscate\Plugin());