diff --git a/.github/workflows/code_checks.yaml b/.github/workflows/code_checks.yaml
index c352bc5..65df556 100644
--- a/.github/workflows/code_checks.yaml
+++ b/.github/workflows/code_checks.yaml
@@ -10,6 +10,35 @@ on:
   workflow_dispatch: ~
 
 jobs:
+  phpstan:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    env:
+      APP_DEBUG: '1' # https://github.com/phpstan/phpstan-symfony/issues/37
+      SYMFONY_REQUIRE: '^7.0'
+      SYMFONY_PHPUNIT_VERSION: '9.5'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.3'
+          tools: flex
+          coverage: none # disable xdebug, pcov
+          ini-values: memory_limit=-1
+
+      - name: Update project dependencies
+        run: |
+          composer update --no-interaction --no-progress --ansi
+          composer require --dev "phpstan/phpstan:^1.10" "phpstan/phpstan-strict-rules:^1.5" "phpstan/phpstan-phpunit: ^1.3" "phpstan/phpstan-deprecation-rules:^1.1"
+
+      - name: Run PHPStan analysis
+        run: |
+          ./vendor/bin/phpstan --version
+          ./vendor/bin/phpstan analyse --no-interaction --no-progress --ansi
+
   phpunit:
     runs-on: ubuntu-latest
     strategy:
@@ -82,30 +111,26 @@ jobs:
   code-coverage:
     name: Code Coverage
     runs-on: ubuntu-latest
+    timeout-minutes: 5
+    env:
+      APP_DEBUG: '1' # https://github.com/phpstan/phpstan-symfony/issues/37
+      SYMFONY_REQUIRE: '^5.0'
+      SYMFONY_PHPUNIT_VERSION: '9.5'
     steps:
-      - name: Checkout code
-        uses: actions/checkout@v3
+      - name: Checkout
+        uses: actions/checkout@v4
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 7.4
+          php-version: '7.4'
+          tools: flex
           coverage: xdebug
+          ini-values: memory_limit=-1
 
-      - name: Get Composer cache directory
-        id: composer-cache
-        run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
-
-      - name: Cache Composer
-        uses: actions/cache@v3
-        with:
-          path: ${{ steps.composer-cache.outputs.dir }}
-          key: ${{ runner.os }}-php-${{ matrix.php }}-composer-${{ hashFiles('**/composer.json **/composer.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-php-${{ matrix.php }}-composer-
-
-      - name: Install PHP dependencies
-        run: composer install --no-interaction
+      - name: Update project dependencies
+        run: |
+          composer update --no-interaction --no-progress --ansi
 
       - name: Run code coverage
         run: vendor/bin/phpunit --coverage-text --coverage-clover=coverage.clover
diff --git a/Tests/Form/Recaptcha3TypeTest.php b/Tests/Form/Recaptcha3TypeTest.php
index 8754896..51ad653 100644
--- a/Tests/Form/Recaptcha3TypeTest.php
+++ b/Tests/Form/Recaptcha3TypeTest.php
@@ -27,14 +27,14 @@ public function testDefaultOptions()
         $form = $this->factory->create(Recaptcha3Type::class);
         $form->setData($data);
 
-        $this->assertTrue($form->isSynchronized());
-        $this->assertEquals($data, $form->getData());
+        self::assertTrue($form->isSynchronized());
+        self::assertEquals($data, $form->getData());
 
         $view = $form->createView();
-        $this->assertSame(self::SITEKEY, $view->vars['site_key']);
-        $this->assertSame(self::HOST, $view->vars['host']);
-        $this->assertSame('homepage', $view->vars['action_name']);
-        $this->assertSame('', $view->vars['script_nonce_csp']);
-        $this->assertTrue($view->vars['enabled']);
+        self::assertSame(self::SITEKEY, $view->vars['site_key']);
+        self::assertSame(self::HOST, $view->vars['host']);
+        self::assertSame('homepage', $view->vars['action_name']);
+        self::assertSame('', $view->vars['script_nonce_csp']);
+        self::assertTrue($view->vars['enabled']);
     }
 }
diff --git a/Tests/Services/HostProviderTest.php b/Tests/Services/HostProviderTest.php
index 5e70a65..9ca43a3 100644
--- a/Tests/Services/HostProviderTest.php
+++ b/Tests/Services/HostProviderTest.php
@@ -3,7 +3,6 @@
 namespace Services;
 
 use Karser\Recaptcha3Bundle\Services\HostProvider;
-use Karser\Recaptcha3Bundle\Services\HostProviderInterface;
 use PHPUnit\Framework\TestCase;
 
 class HostProviderTest extends TestCase
@@ -12,7 +11,7 @@ class HostProviderTest extends TestCase
     public function test__construct()
     {
         $hostProvider = new HostProvider('www.a-domain.tld');
-        self::assertInstanceOf(HostProviderInterface::class, $hostProvider);
+        self::assertSame('www.a-domain.tld', $hostProvider->getHost());
     }
 
     public function testGetHost()
diff --git a/Tests/TestKernel.php b/Tests/TestKernel.php
index ab37c13..a1c701c 100644
--- a/Tests/TestKernel.php
+++ b/Tests/TestKernel.php
@@ -22,7 +22,7 @@ public function setConfigurationFilename($filename)
     /**
      * {@inheritdoc}
      */
-    public function registerBundles(): array
+    public function registerBundles(): iterable
     {
         return [
             new \Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
diff --git a/Tests/Validator/Constraints/Recaptcha3ValidatorTest.php b/Tests/Validator/Constraints/Recaptcha3ValidatorTest.php
index 140a76c..7e9d337 100644
--- a/Tests/Validator/Constraints/Recaptcha3ValidatorTest.php
+++ b/Tests/Validator/Constraints/Recaptcha3ValidatorTest.php
@@ -105,7 +105,7 @@ public function testLastResponse()
         $this->recaptcha->nextSuccess = true;
 
         $validator = new Recaptcha3Validator($this->recaptcha, $enabled = true, $this->resolver);
-        self::assertNull($this->validator->getLastResponse());
+        self::assertNull($validator->getLastResponse());
 
         $validator->validate('test', new Recaptcha3());
         self::assertNotNull($validator->getLastResponse());
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..4374b9b
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,24 @@
+includes:
+    - vendor/phpstan/phpstan-deprecation-rules/rules.neon
+    - vendor/phpstan/phpstan-strict-rules/rules.neon
+
+parameters:
+    level: 5
+    reportUnmatchedIgnoredErrors: false
+    checkMissingIterableValueType: false
+    checkGenericClassInNonGenericObjectType: false
+    inferPrivatePropertyTypeFromConstructor: true
+    paths:
+        - %currentWorkingDirectory%
+    ignoreErrors:
+        - '#Class Symfony\\Component\\Config\\Definition\\Builder\\TreeBuilder constructor invoked with 0 parameters, 1-3 required#'
+        - '#Call to an undefined method Symfony\\Component\\Config\\Definition\\Builder\\TreeBuilder::root\(\)#'
+        - '#Call to function method_exists\(\) with .*?TreeBuilder.*? and .*?getRootNode.*? will always evaluate to true#'
+        - '#Comparison operation "<" between 70006 and 50200 is always false#'
+        - '#Comparison operation ">=" between 7 and 6 is always true#'
+        - '#Else branch is unreachable because ternary operator condition is always true#'
+
+    excludePaths:
+        - %currentWorkingDirectory%/.github/*
+        - %currentWorkingDirectory%/.idea/*
+        - %currentWorkingDirectory%/vendor/*