diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index 6d9f502..cfcf0af 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
+        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
         os: ['ubuntu-latest']
 
     steps:
@@ -31,7 +31,9 @@ jobs:
           tools: phpcs
 
       - name: Setup dependencies
-        run: composer require -n --no-progress overtrue/phplint
+        run: |
+          composer require -n --no-progress overtrue/phplint phpstan/phpstan
+          sudo cp -R vendor /usr/share/icinga-php
 
       - name: PHP Lint
         if: ${{ ! cancelled() }}
@@ -43,7 +45,7 @@ jobs:
 
       - name: PHPStan
         if: ${{ ! cancelled() }}
-        uses: php-actions/phpstan@v3
+        run: ./vendor/bin/phpstan analyse
 
   test:
     name: Unit tests with php ${{ matrix.php }} on ${{ matrix.os }}
@@ -55,7 +57,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
+        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
         os: ['ubuntu-latest']
 
     steps:
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
deleted file mode 100644
index c8aa3b3..0000000
--- a/phpstan-baseline.neon
+++ /dev/null
@@ -1,96 +0,0 @@
-parameters:
-	ignoreErrors:
-		-
-			message: "#^Method ipl\\\\Validator\\\\BetweenValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/BetweenValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\DeferredInArrayValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/DeferredInArrayValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\DeferredInArrayValidator\\:\\:getHaystack\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/DeferredInArrayValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\EmailAddressValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/EmailAddressValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\FileValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/FileValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\GreaterThanValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/GreaterThanValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\InArrayValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/InArrayValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\InArrayValidator\\:\\:findInvalid\\(\\) has parameter \\$values with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/InArrayValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\InArrayValidator\\:\\:findInvalid\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/InArrayValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\InArrayValidator\\:\\:getHaystack\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/InArrayValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\InArrayValidator\\:\\:setHaystack\\(\\) has parameter \\$haystack with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/InArrayValidator.php
-
-		-
-			message: "#^Property ipl\\\\Validator\\\\InArrayValidator\\:\\:\\$haystack type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/InArrayValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\LessThanValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/LessThanValidator.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\StringLengthValidator\\:\\:__construct\\(\\) has parameter \\$options with no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/StringLengthValidator.php
-
-		-
-			message: "#^Class ipl\\\\Validator\\\\ValidatorChain implements generic interface IteratorAggregate but does not specify its types\\: TKey, TValue$#"
-			count: 1
-			path: src/ValidatorChain.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\ValidatorChain\\:\\:addValidators\\(\\) has parameter \\$validators with no value type specified in iterable type iterable\\.$#"
-			count: 1
-			path: src/ValidatorChain.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\ValidatorChain\\:\\:getValidatorsThatBreakTheChain\\(\\) return type with generic class SplObjectStorage does not specify its types\\: TObject, TData$#"
-			count: 1
-			path: src/ValidatorChain.php
-
-		-
-			message: "#^Method ipl\\\\Validator\\\\ValidatorChain\\:\\:toArray\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: src/ValidatorChain.php
-
-		-
-			message: "#^Property ipl\\\\Validator\\\\ValidatorChain\\:\\:\\$validatorsThatBreakTheChain with generic class SplObjectStorage does not specify its types\\: TObject, TData$#"
-			count: 1
-			path: src/ValidatorChain.php
diff --git a/phpstan.neon b/phpstan.neon
index b0ed57d..303e5ef 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,6 +1,3 @@
-includes:
-	- phpstan-baseline.neon
-
 parameters:
     level: max
 
@@ -12,7 +9,7 @@ parameters:
         - src
 
     scanDirectories:
-        - vendor
+        - /usr/share/icinga-php
 
     ignoreErrors:
         -
diff --git a/src/BetweenValidator.php b/src/BetweenValidator.php
index 90a6146..c8dc026 100644
--- a/src/BetweenValidator.php
+++ b/src/BetweenValidator.php
@@ -40,7 +40,7 @@ class BetweenValidator extends BaseValidator
      *
      * - inclusive: (bool) Whether inclusive border values, default true
      *
-     * @param array $options
+     * @param array{min: int|float, max: int|float, inclusive?: bool} $options
      *
      * @throws Exception When required option is missing
      */
diff --git a/src/DeferredInArrayValidator.php b/src/DeferredInArrayValidator.php
index 55b9b83..fa0ba5d 100644
--- a/src/DeferredInArrayValidator.php
+++ b/src/DeferredInArrayValidator.php
@@ -15,7 +15,7 @@ class DeferredInArrayValidator extends InArrayValidator
      *
      * **Required parameter:**
      *
-     * - `callback`: (`callable`) The callback to create haystack
+     * - `callback`: (`callable`) The callback to create the haystack
      *
      * **Optional parameter:**
      *
@@ -23,8 +23,8 @@ class DeferredInArrayValidator extends InArrayValidator
      *
      *  * `strict`: (`bool`) Whether the types of the needle in the haystack should also match, default `false`
      *
-     * @param callable $callback Validation callback
-     * @param array $options
+     * @param callable $callback The callback to create the haystack
+     * @param array{haystack?: mixed[], strict?: bool} $options
      */
     public function __construct(callable $callback, array $options = [])
     {
diff --git a/src/EmailAddressValidator.php b/src/EmailAddressValidator.php
index f98e18e..e9dc2a7 100644
--- a/src/EmailAddressValidator.php
+++ b/src/EmailAddressValidator.php
@@ -40,7 +40,7 @@ class EmailAddressValidator extends BaseValidator
      * 'mx'   => If an MX check should be enabled, boolean
      * 'deep' => If a deep MX check should be enabled, boolean
      *
-     * @param array $options
+     * @param array{max?: bool, deep?: bool} $options
      *
      * @throws Exception
      */
diff --git a/src/FileValidator.php b/src/FileValidator.php
index 4ba2888..bc435cc 100644
--- a/src/FileValidator.php
+++ b/src/FileValidator.php
@@ -34,6 +34,8 @@ class FileValidator extends BaseValidator
      * - maxSize: (int) Maximum allowed file size, by default no limit
      * - maxFileNameLength: (int) Maximum allowed file name length, by default no limit
      * - mimeType: (array) Allowed mime types, by default no restriction
+     *
+     * @param array{minSize?: int, maxSize?: int, maxFileNameLength?: int, mimeType?: string[]} $options
      */
     public function __construct(array $options = [])
     {
@@ -243,7 +245,7 @@ private function validateFile(UploadedFileInterface $file): bool
                     $this->translate('File %s is of type %s. Only %s allowed.'),
                     $file->getClientFilename(),
                     $file->getClientMediaType(),
-                    implode(', ', $this->allowedMimeTypes)
+                    implode(', ', $this->allowedMimeTypes ?? [])
                 ));
 
                 $isValid = false;
diff --git a/src/GreaterThanValidator.php b/src/GreaterThanValidator.php
index 58166c6..177fa42 100644
--- a/src/GreaterThanValidator.php
+++ b/src/GreaterThanValidator.php
@@ -19,6 +19,8 @@ class GreaterThanValidator extends BaseValidator
      *
      * Optional options:
      * - min: (int|float) Comparison value for greater than, default 0
+     *
+     * @param array{min?: int|float} $options
      */
     public function __construct(array $options = [])
     {
diff --git a/src/InArrayValidator.php b/src/InArrayValidator.php
index 32868d8..f3e67e7 100644
--- a/src/InArrayValidator.php
+++ b/src/InArrayValidator.php
@@ -11,7 +11,7 @@ class InArrayValidator extends BaseValidator
 {
     use Translation;
 
-    /** @var ?array The array */
+    /** @var ?mixed[] The array */
     protected $haystack;
 
     /** @var bool Whether the types of the needle in the haystack should also match */
@@ -25,7 +25,7 @@ class InArrayValidator extends BaseValidator
      * * `haystack`: (`array`) The array
      * * `strict`: (`bool`) Whether the types of the needle in the haystack should also match, default `false`
      *
-     * @param array $options
+     * @param array{haystack?: mixed[], strict?: bool} $options
      */
     public function __construct(array $options = [])
     {
@@ -39,7 +39,7 @@ public function __construct(array $options = [])
     /**
      * Get the haystack
      *
-     * @return array
+     * @return mixed[]
      */
     public function getHaystack(): array
     {
@@ -49,7 +49,7 @@ public function getHaystack(): array
     /**
      * Set the haystack
      *
-     * @param array $haystack
+     * @param mixed[] $haystack
      *
      * @return $this
      */
@@ -110,9 +110,9 @@ public function isValid($value): bool
     /**
      * Get the values from the specified array that are not present in the haystack
      *
-     * @param array $values
+     * @param mixed[] $values
      *
-     * @return array Values not found in the haystack
+     * @return mixed[] Values not found in the haystack
      */
     protected function findInvalid(array $values = []): array
     {
diff --git a/src/LessThanValidator.php b/src/LessThanValidator.php
index 50b566f..db80e1a 100644
--- a/src/LessThanValidator.php
+++ b/src/LessThanValidator.php
@@ -19,6 +19,8 @@ class LessThanValidator extends BaseValidator
      *
      * Optional options:
      * - max: (int|float) Comparison value for less than, default 0
+     *
+     * @param array{max?: int|float} $options
      */
     public function __construct(array $options = [])
     {
diff --git a/src/StringLengthValidator.php b/src/StringLengthValidator.php
index 0322c1c..d4dd44b 100644
--- a/src/StringLengthValidator.php
+++ b/src/StringLengthValidator.php
@@ -26,9 +26,11 @@ class StringLengthValidator extends BaseValidator
      * Create a new StringLengthValidator
      *
      * Optional options:
-     * - min: (scalar) Minimum required string length, default 0
-     * - max: (scalar) Maximum required string length, default null
-     * - encoding: (string) Encoding type, default null
+     * - min: (int) Minimum required string length, default 0
+     * - max: (int) Maximum required string length, default none
+     * - encoding: (string) Encoding type, default none
+     *
+     * @param array{min?: int, max?: int, encoding?: string} $options
      */
     public function __construct(array $options = [])
     {
diff --git a/src/ValidatorChain.php b/src/ValidatorChain.php
index 92249c2..8f0b9f3 100644
--- a/src/ValidatorChain.php
+++ b/src/ValidatorChain.php
@@ -15,6 +15,7 @@
 
 use function ipl\Stdlib\get_php_type;
 
+/** @implements IteratorAggregate<int, Validator> */
 class ValidatorChain implements Countable, IteratorAggregate, Validator
 {
     use Messages;
@@ -23,10 +24,10 @@ class ValidatorChain implements Countable, IteratorAggregate, Validator
     /** Default priority at which validators are added */
     const DEFAULT_PRIORITY = 1;
 
-    /** @var PriorityQueue Validator chain */
+    /** @var PriorityQueue<int, Validator> Validator chain */
     protected $validators;
 
-    /** @var SplObjectStorage Validators that break the chain on failure */
+    /** @var SplObjectStorage<Validator, null> Validators that break the chain on failure */
     protected $validatorsThatBreakTheChain;
 
     /**
@@ -43,7 +44,7 @@ public function __construct()
     /**
      * Get the validators that break the chain
      *
-     * @return SplObjectStorage
+     * @return SplObjectStorage<Validator, null>
      */
     public function getValidatorsThatBreakTheChain()
     {
@@ -76,7 +77,7 @@ public function add(Validator $validator, $breakChainOnFailure = false, $priorit
     /**
      * Add the validators from the given validator specification to the chain
      *
-     * @param iterable $validators
+     * @param static|Traversable<int|string, mixed> $validators
      *
      * @return $this
      *
@@ -240,11 +241,14 @@ public function __clone()
     /**
      * Export the chain as array
      *
-     * @return array
+     * @return Validator[]
      */
     public function toArray()
     {
-        return array_values(iterator_to_array($this));
+        /** @var Validator[] $validators */
+        $validators = iterator_to_array($this);
+
+        return array_values($validators);
     }
 
     public function count(): int
@@ -255,7 +259,7 @@ public function count(): int
     /**
      * Get an iterator for traversing the validators
      *
-     * @return Validator[]|PriorityQueue
+     * @return PriorityQueue<int, Validator>
      */
     public function getIterator(): Traversable
     {