diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
new file mode 100644
index 00000000..9979744a
--- /dev/null
+++ b/.github/workflows/phpstan.yml
@@ -0,0 +1,26 @@
+name: PHPStan
+
+on:
+    push:
+        paths:
+            - '**.php'
+            - 'phpstan.neon.dist'
+
+jobs:
+    phpstan:
+        name: phpstan
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v4
+
+            - name: Setup PHP
+              uses: shivammathur/setup-php@v2
+              with:
+                  php-version: '8.2'
+                  coverage: none
+
+            - name: Install composer dependencies
+              uses: ramsey/composer-install@v2
+
+            - name: Run PHPStan
+              run: ./vendor/bin/phpstan --error-format=github
diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 088ac821..6978a60f 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -25,6 +25,7 @@ jobs:
                       testbench: 9.*
                       carbon: ^2.63
                     - laravel: 10.*
+                      php: 8.0
                       testbench: 8.*
 
         name: P${{ matrix.php }} - L${{ matrix.laravel }} - ${{ matrix.stability }} - ${{ matrix.os }}
@@ -52,8 +53,6 @@ jobs:
                     --health-retries 5
 
         steps:
-
-
             - name: Checkout code
               uses: actions/checkout@v4
 
diff --git a/composer.json b/composer.json
index b8fc724a..3167ab0b 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,10 @@
     "require-dev": {
         "ext-json": "*",
         "mockery/mockery": "^1.4",
+        "nunomaduro/larastan": "^2.0",
         "orchestra/testbench": "^7.0|^8.0",
+        "phpunit/phpunit": "^9.6.11",
+        "rector/rector": "^0.18.10",
         "pestphp/pest": "^2.0",
         "spatie/invade": "^2.0",
         "spatie/laravel-ray": "^1.28"
@@ -47,7 +50,9 @@
     },
     "scripts": {
         "test": "vendor/bin/pest",
-        "test-coverage": "phpunit --coverage-html coverage"
+        "test-coverage": "phpunit --coverage-html coverage",
+        "analyse": "vendor/bin/phpstan analyse --ansi --memory-limit=4G",
+        "baseline": "vendor/bin/phpstan analyse --generate-baseline --memory-limit=4G"
     },
     "config": {
         "sort-packages": true,
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
new file mode 100644
index 00000000..85249926
--- /dev/null
+++ b/phpstan-baseline.neon
@@ -0,0 +1,36 @@
+parameters:
+	ignoreErrors:
+		-
+			message: "#^Parameter \\#1 \\$keys of method Illuminate\\\\Support\\\\Collection\\<int,string\\>\\:\\:except\\(\\) expects array\\<int\\>\\|Illuminate\\\\Support\\\\Enumerable\\<\\(int\\|string\\), int\\>\\|string, int\\<\\-1, max\\> given\\.$#"
+			count: 1
+			path: src/Filters/FiltersExact.php
+
+		-
+			message: "#^Call to an undefined method ReflectionType\\:\\:getName\\(\\)\\.$#"
+			count: 2
+			path: src/Filters/FiltersScope.php
+
+		-
+			message: "#^Call to an undefined method ReflectionType\\:\\:isBuiltin\\(\\)\\.$#"
+			count: 1
+			path: src/Filters/FiltersScope.php
+
+		-
+			message: "#^Call to an undefined method Illuminate\\\\Database\\\\Eloquent\\\\Builder\\<TModelClass of Illuminate\\\\Database\\\\Eloquent\\\\Model\\>\\:\\:onlyTrashed\\(\\)\\.$#"
+			count: 1
+			path: src/Filters/FiltersTrashed.php
+
+		-
+			message: "#^Call to an undefined method Illuminate\\\\Database\\\\Eloquent\\\\Builder\\<TModelClass of Illuminate\\\\Database\\\\Eloquent\\\\Model\\>\\:\\:withTrashed\\(\\)\\.$#"
+			count: 1
+			path: src/Filters/FiltersTrashed.php
+
+		-
+			message: "#^Call to an undefined method Illuminate\\\\Database\\\\Eloquent\\\\Builder\\<TModelClass of Illuminate\\\\Database\\\\Eloquent\\\\Model\\>\\:\\:withoutTrashed\\(\\)\\.$#"
+			count: 1
+			path: src/Filters/FiltersTrashed.php
+
+		-
+			message: "#^PHPDoc tag @return with type Spatie\\\\QueryBuilder\\\\QueryBuilder is not subtype of native type static\\(Spatie\\\\QueryBuilder\\\\QueryBuilder\\)\\.$#"
+			count: 2
+			path: src/QueryBuilder.php
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
new file mode 100644
index 00000000..c590d9e3
--- /dev/null
+++ b/phpstan.neon.dist
@@ -0,0 +1,28 @@
+includes:
+    - ./vendor/nunomaduro/larastan/extension.neon
+    - phpstan-baseline.neon
+
+parameters:
+
+    paths:
+        - src/
+        - config/
+        - database/
+
+    # Level 9 is the highest level
+    level: 5
+
+    checkModelProperties: true
+    checkOctaneCompatibility: true
+    checkMissingIterableValueType: false
+    reportUnmatchedIgnoredErrors: false
+    noUnnecessaryCollectionCall: true
+    checkNullables: true
+    checkGenericClassInNonGenericObjectType: false
+    treatPhpDocTypesAsCertain: false
+
+    ignoreErrors:
+        - '#Unsafe usage of new static#'
+        - '#PHPDoc tag @var#'
+
+#    excludePaths:
diff --git a/rector.php b/rector.php
new file mode 100644
index 00000000..afb0ea81
--- /dev/null
+++ b/rector.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\CodeQuality\Rector\Class_\InlineConstructorDefaultToPropertyRector;
+use Rector\Config\RectorConfig;
+use Rector\Php74\Rector\Assign\NullCoalescingOperatorRector;
+use Rector\Php74\Rector\Closure\ClosureToArrowFunctionRector;
+use Rector\Set\ValueObject\LevelSetList;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->paths([
+        __DIR__ . '/config',
+        __DIR__ . '/src',
+        __DIR__ . '/tests',
+    ]);
+
+    // register a single rule
+    //$rectorConfig->rule(InlineConstructorDefaultToPropertyRector::class);
+
+    // define sets of rules
+        $rectorConfig->sets([
+            LevelSetList::UP_TO_PHP_80
+        ]);
+
+        $rectorConfig->skip([
+            ClosureToArrowFunctionRector::class,
+            NullCoalescingOperatorRector::class,
+        ]);
+};
diff --git a/src/AllowedFilter.php b/src/AllowedFilter.php
index 7c0ac0cd..7383ea89 100644
--- a/src/AllowedFilter.php
+++ b/src/AllowedFilter.php
@@ -14,39 +14,30 @@
 
 class AllowedFilter
 {
-    /** @var Filter */
-    protected $filterClass;
+    protected string $internalName;
 
-    /** @var string */
-    protected $name;
+    protected Filter $filterClass;
 
-    /** @var string */
-    protected $internalName;
-
-    /** @var \Illuminate\Support\Collection */
-    protected $ignored;
+    protected Collection $ignored;
 
     /** @var mixed */
     protected $default;
 
-    /** @var bool */
-    protected $hasDefault = false;
-
-    /** @var bool */
-    protected $nullable = false;
-
-    public function __construct(string $name, Filter $filterClass, ?string $internalName = null)
-    {
-        $this->name = $name;
+    protected bool $hasDefault = false;
 
-        $this->filterClass = $filterClass;
+    protected bool $nullable = false;
 
+    public function __construct(
+        protected string $name,
+        protected Filter $filterClass,
+        ?string $internalName = null
+    ) {
         $this->ignored = Collection::make();
 
         $this->internalName = $internalName ?? $name;
     }
 
-    public function filter(QueryBuilder $query, $value)
+    public function filter(QueryBuilder $query, $value): void
     {
         $valueToFilter = $this->resolveValueForFiltering($value);
 
diff --git a/src/AllowedInclude.php b/src/AllowedInclude.php
index cce9b06b..df07303a 100644
--- a/src/AllowedInclude.php
+++ b/src/AllowedInclude.php
@@ -13,19 +13,13 @@
 
 class AllowedInclude
 {
-    /** @var string */
-    protected $name;
+    protected string $internalName;
 
-    /** @var IncludeInterface */
-    protected $includeClass;
-
-    /** @var string|null */
-    protected $internalName;
-
-    public function __construct(string $name, IncludeInterface $includeClass, ?string $internalName = null)
-    {
-        $this->name = $name;
-        $this->includeClass = $includeClass;
+    public function __construct(
+        protected string $name,
+        protected IncludeInterface $includeClass,
+        ?string $internalName = null
+    ) {
         $this->internalName = $internalName ?? $this->name;
     }
 
diff --git a/src/AllowedSort.php b/src/AllowedSort.php
index 816c3c3f..a94f71e7 100644
--- a/src/AllowedSort.php
+++ b/src/AllowedSort.php
@@ -10,24 +10,14 @@
 
 class AllowedSort
 {
-    /** @var \Spatie\QueryBuilder\Sorts\Sort */
-    protected $sortClass;
+    protected string $defaultDirection;
 
-    /** @var string */
-    protected $name;
+    protected string $internalName;
 
-    /** @var string */
-    protected $defaultDirection;
-
-    /** @var string */
-    protected $internalName;
-
-    public function __construct(string $name, Sort $sortClass, ?string $internalName = null)
+    public function __construct(protected string $name, protected Sort $sortClass, ?string $internalName = null)
     {
         $this->name = ltrim($name, '-');
 
-        $this->sortClass = $sortClass;
-
         $this->defaultDirection = static::parseSortDirection($name);
 
         $this->internalName = $internalName ?? $this->name;
@@ -35,7 +25,7 @@ public function __construct(string $name, Sort $sortClass, ?string $internalName
 
     public static function parseSortDirection(string $name): string
     {
-        return strpos($name, '-') === 0 ? SortDirection::DESCENDING : SortDirection::ASCENDING;
+        return str_starts_with($name, '-') ? SortDirection::DESCENDING : SortDirection::ASCENDING;
     }
 
     public function sort(QueryBuilder $query, ?bool $descending = null): void
@@ -75,7 +65,7 @@ public function getInternalName(): string
         return $this->internalName;
     }
 
-    public function defaultDirection(string $defaultDirection)
+    public function defaultDirection(string $defaultDirection): static
     {
         if (! in_array($defaultDirection, [
             SortDirection::ASCENDING,
diff --git a/src/Concerns/AddsFieldsToQuery.php b/src/Concerns/AddsFieldsToQuery.php
index 71b26f58..120c000e 100644
--- a/src/Concerns/AddsFieldsToQuery.php
+++ b/src/Concerns/AddsFieldsToQuery.php
@@ -32,7 +32,7 @@ public function allowedFields($fields): static
         return $this;
     }
 
-    protected function addRequestedModelFieldsToQuery()
+    protected function addRequestedModelFieldsToQuery(): void
     {
         $modelTableName = $this->getModel()->getTable();
 
@@ -72,7 +72,7 @@ public function getRequestedFieldsForRelatedTable(string $relation): array
         return $fields;
     }
 
-    protected function ensureAllFieldsExist()
+    protected function ensureAllFieldsExist(): void
     {
         $modelTable = $this->getModel()->getTable();
 
diff --git a/src/Concerns/AddsIncludesToQuery.php b/src/Concerns/AddsIncludesToQuery.php
index 11f4c554..1dee0ca5 100644
--- a/src/Concerns/AddsIncludesToQuery.php
+++ b/src/Concerns/AddsIncludesToQuery.php
@@ -52,12 +52,12 @@ public function allowedIncludes($includes): static
         return $this;
     }
 
-    protected function addIncludesToQuery(Collection $includes)
+    protected function addIncludesToQuery(Collection $includes): void
     {
         $includes->each(function ($include) {
             $include = $this->findInclude($include);
 
-            $include->include($this);
+            $include?->include($this);
         });
     }
 
@@ -69,7 +69,7 @@ protected function findInclude(string $include): ?AllowedInclude
             });
     }
 
-    protected function ensureAllIncludesExist()
+    protected function ensureAllIncludesExist(): void
     {
         if (config('query-builder.disable_invalid_includes_query_exception', false)) {
             return;
@@ -77,7 +77,7 @@ protected function ensureAllIncludesExist()
 
         $includes = $this->request->includes();
 
-        $allowedIncludeNames = $this->allowedIncludes->map(function (AllowedInclude $allowedInclude) {
+        $allowedIncludeNames = $this->allowedIncludes?->map(function (AllowedInclude $allowedInclude) {
             return $allowedInclude->getName();
         });
 
diff --git a/src/Concerns/FiltersQuery.php b/src/Concerns/FiltersQuery.php
index 58183421..9e932c23 100644
--- a/src/Concerns/FiltersQuery.php
+++ b/src/Concerns/FiltersQuery.php
@@ -2,13 +2,13 @@
 
 namespace Spatie\QueryBuilder\Concerns;
 
+use Illuminate\Support\Collection;
 use Spatie\QueryBuilder\AllowedFilter;
 use Spatie\QueryBuilder\Exceptions\InvalidFilterQuery;
 
 trait FiltersQuery
 {
-    /** @var \Illuminate\Support\Collection */
-    protected $allowedFilters;
+    protected Collection $allowedFilters;
 
     public function allowedFilters($filters): static
     {
@@ -29,7 +29,7 @@ public function allowedFilters($filters): static
         return $this;
     }
 
-    protected function addFiltersToQuery()
+    protected function addFiltersToQuery(): void
     {
         $this->allowedFilters->each(function (AllowedFilter $filter) {
             if ($this->isFilterRequested($filter)) {
@@ -41,8 +41,6 @@ protected function addFiltersToQuery()
 
             if ($filter->hasDefault()) {
                 $filter->filter($this, $filter->getDefault());
-
-                return;
             }
         });
     }
@@ -60,7 +58,7 @@ protected function isFilterRequested(AllowedFilter $allowedFilter): bool
         return $this->request->filters()->has($allowedFilter->getName());
     }
 
-    protected function ensureAllFiltersExist()
+    protected function ensureAllFiltersExist(): void
     {
         if (config('query-builder.disable_invalid_filter_query_exception', false)) {
             return;
diff --git a/src/Concerns/SortsQuery.php b/src/Concerns/SortsQuery.php
index b3b68b04..d56ebbea 100644
--- a/src/Concerns/SortsQuery.php
+++ b/src/Concerns/SortsQuery.php
@@ -2,13 +2,13 @@
 
 namespace Spatie\QueryBuilder\Concerns;
 
+use Illuminate\Support\Collection;
 use Spatie\QueryBuilder\AllowedSort;
 use Spatie\QueryBuilder\Exceptions\InvalidSortQuery;
 
 trait SortsQuery
 {
-    /** @var \Illuminate\Support\Collection */
-    protected $allowedSorts;
+    protected Collection $allowedSorts;
 
     public function allowedSorts($sorts): static
     {
@@ -71,7 +71,7 @@ public function defaultSorts($sorts): static
         return $this;
     }
 
-    protected function addRequestedSortsToQuery()
+    protected function addRequestedSortsToQuery(): void
     {
         $this->request->sorts()
             ->each(function (string $property) {
diff --git a/src/Exceptions/InvalidAppendQuery.php b/src/Exceptions/InvalidAppendQuery.php
index 04082953..6a512644 100644
--- a/src/Exceptions/InvalidAppendQuery.php
+++ b/src/Exceptions/InvalidAppendQuery.php
@@ -7,17 +7,10 @@
 
 class InvalidAppendQuery extends InvalidQuery
 {
-    /** @var \Illuminate\Support\Collection */
-    public $appendsNotAllowed;
-
-    /** @var \Illuminate\Support\Collection */
-    public $allowedAppends;
-
-    public function __construct(Collection $appendsNotAllowed, Collection $allowedAppends)
-    {
-        $this->appendsNotAllowed = $appendsNotAllowed;
-        $this->allowedAppends = $allowedAppends;
-
+    public function __construct(
+        public Collection $appendsNotAllowed,
+        public Collection $allowedAppends
+    ) {
         $appendsNotAllowed = $appendsNotAllowed->implode(', ');
         $allowedAppends = $allowedAppends->implode(', ');
         $message = "Requested append(s) `{$appendsNotAllowed}` are not allowed. Allowed append(s) are `{$allowedAppends}`.";
@@ -25,7 +18,7 @@ public function __construct(Collection $appendsNotAllowed, Collection $allowedAp
         parent::__construct(Response::HTTP_BAD_REQUEST, $message);
     }
 
-    public static function appendsNotAllowed(Collection $appendsNotAllowed, Collection $allowedAppends)
+    public static function appendsNotAllowed(Collection $appendsNotAllowed, Collection $allowedAppends): static
     {
         return new static(...func_get_args());
     }
diff --git a/src/Exceptions/InvalidFieldQuery.php b/src/Exceptions/InvalidFieldQuery.php
index bc89d6cc..77d22866 100644
--- a/src/Exceptions/InvalidFieldQuery.php
+++ b/src/Exceptions/InvalidFieldQuery.php
@@ -7,17 +7,10 @@
 
 class InvalidFieldQuery extends InvalidQuery
 {
-    /** @var \Illuminate\Support\Collection */
-    public $unknownFields;
-
-    /** @var \Illuminate\Support\Collection */
-    public $allowedFields;
-
-    public function __construct(Collection $unknownFields, Collection $allowedFields)
-    {
-        $this->unknownFields = $unknownFields;
-        $this->allowedFields = $allowedFields;
-
+    public function __construct(
+        public Collection $unknownFields,
+        public Collection $allowedFields
+    ) {
         $unknownFields = $unknownFields->implode(', ');
         $allowedFields = $allowedFields->implode(', ');
         $message = "Requested field(s) `{$unknownFields}` are not allowed. Allowed field(s) are `{$allowedFields}`.";
@@ -25,7 +18,7 @@ public function __construct(Collection $unknownFields, Collection $allowedFields
         parent::__construct(Response::HTTP_BAD_REQUEST, $message);
     }
 
-    public static function fieldsNotAllowed(Collection $unknownFields, Collection $allowedFields)
+    public static function fieldsNotAllowed(Collection $unknownFields, Collection $allowedFields): static
     {
         return new static(...func_get_args());
     }
diff --git a/src/Exceptions/InvalidFilterQuery.php b/src/Exceptions/InvalidFilterQuery.php
index 8e6c8766..9281bd8f 100644
--- a/src/Exceptions/InvalidFilterQuery.php
+++ b/src/Exceptions/InvalidFilterQuery.php
@@ -7,17 +7,10 @@
 
 class InvalidFilterQuery extends InvalidQuery
 {
-    /** @var \Illuminate\Support\Collection */
-    public $unknownFilters;
-
-    /** @var \Illuminate\Support\Collection */
-    public $allowedFilters;
-
-    public function __construct(Collection $unknownFilters, Collection $allowedFilters)
-    {
-        $this->unknownFilters = $unknownFilters;
-        $this->allowedFilters = $allowedFilters;
-
+    public function __construct(
+        public Collection $unknownFilters,
+        public Collection $allowedFilters
+    ) {
         $unknownFilters = $this->unknownFilters->implode(', ');
         $allowedFilters = $this->allowedFilters->implode(', ');
         $message = "Requested filter(s) `{$unknownFilters}` are not allowed. Allowed filter(s) are `{$allowedFilters}`.";
@@ -25,7 +18,7 @@ public function __construct(Collection $unknownFilters, Collection $allowedFilte
         parent::__construct(Response::HTTP_BAD_REQUEST, $message);
     }
 
-    public static function filtersNotAllowed(Collection $unknownFilters, Collection $allowedFilters)
+    public static function filtersNotAllowed(Collection $unknownFilters, Collection $allowedFilters): static
     {
         return new static(...func_get_args());
     }
diff --git a/src/Exceptions/InvalidFilterValue.php b/src/Exceptions/InvalidFilterValue.php
index 473568a6..a01d636e 100644
--- a/src/Exceptions/InvalidFilterValue.php
+++ b/src/Exceptions/InvalidFilterValue.php
@@ -6,7 +6,7 @@
 
 class InvalidFilterValue extends Exception
 {
-    public static function make($value)
+    public static function make($value): static
     {
         return new static("Filter value `{$value}` is invalid.");
     }
diff --git a/src/Exceptions/InvalidIncludeQuery.php b/src/Exceptions/InvalidIncludeQuery.php
index c214ae21..4540e8f1 100644
--- a/src/Exceptions/InvalidIncludeQuery.php
+++ b/src/Exceptions/InvalidIncludeQuery.php
@@ -7,17 +7,10 @@
 
 class InvalidIncludeQuery extends InvalidQuery
 {
-    /** @var \Illuminate\Support\Collection */
-    public $unknownIncludes;
-
-    /** @var \Illuminate\Support\Collection */
-    public $allowedIncludes;
-
-    public function __construct(Collection $unknownIncludes, Collection $allowedIncludes)
-    {
-        $this->unknownIncludes = $unknownIncludes;
-        $this->allowedIncludes = $allowedIncludes;
-
+    public function __construct(
+        public Collection $unknownIncludes,
+        public Collection $allowedIncludes
+    ) {
         $unknownIncludes = $unknownIncludes->implode(', ');
 
         $message = "Requested include(s) `{$unknownIncludes}` are not allowed. ";
@@ -32,7 +25,7 @@ public function __construct(Collection $unknownIncludes, Collection $allowedIncl
         parent::__construct(Response::HTTP_BAD_REQUEST, $message);
     }
 
-    public static function includesNotAllowed(Collection $unknownIncludes, Collection $allowedIncludes)
+    public static function includesNotAllowed(Collection $unknownIncludes, Collection $allowedIncludes): static
     {
         return new static(...func_get_args());
     }
diff --git a/src/Exceptions/InvalidSortQuery.php b/src/Exceptions/InvalidSortQuery.php
index ae4219ed..dc952961 100644
--- a/src/Exceptions/InvalidSortQuery.php
+++ b/src/Exceptions/InvalidSortQuery.php
@@ -7,25 +7,19 @@
 
 class InvalidSortQuery extends InvalidQuery
 {
-    /** @var \Illuminate\Support\Collection */
-    public $unknownSorts;
-
-    /** @var \Illuminate\Support\Collection */
-    public $allowedSorts;
-
-    public function __construct(Collection $unknownSorts, Collection $allowedSorts)
-    {
-        $this->unknownSorts = $unknownSorts;
-        $this->allowedSorts = $allowedSorts;
-
+    public function __construct(
+        public Collection $unknownSorts,
+        public Collection $allowedSorts
+    ) {
         $allowedSorts = $allowedSorts->implode(', ');
         $unknownSorts = $unknownSorts->implode(', ');
+
         $message = "Requested sort(s) `{$unknownSorts}` is not allowed. Allowed sort(s) are `{$allowedSorts}`.";
 
         parent::__construct(Response::HTTP_BAD_REQUEST, $message);
     }
 
-    public static function sortsNotAllowed(Collection $unknownSorts, Collection $allowedSorts)
+    public static function sortsNotAllowed(Collection $unknownSorts, Collection $allowedSorts): static
     {
         return new static(...func_get_args());
     }
diff --git a/src/Exceptions/InvalidSubject.php b/src/Exceptions/InvalidSubject.php
deleted file mode 100644
index 3a4130a1..00000000
--- a/src/Exceptions/InvalidSubject.php
+++ /dev/null
@@ -1,20 +0,0 @@
-<?php
-
-namespace Spatie\QueryBuilder\Exceptions;
-
-use InvalidArgumentException;
-
-class InvalidSubject extends InvalidArgumentException
-{
-    public static function make($subject)
-    {
-        return new static(
-            sprintf(
-                'Subject %s is invalid.',
-                is_object($subject)
-                    ? sprintf('class `%s`', get_class($subject))
-                    : sprintf('type `%s`', gettype($subject))
-            )
-        );
-    }
-}
diff --git a/src/Filters/FiltersExact.php b/src/Filters/FiltersExact.php
index a3c3f008..f1e7f234 100644
--- a/src/Filters/FiltersExact.php
+++ b/src/Filters/FiltersExact.php
@@ -13,14 +13,10 @@
  */
 class FiltersExact implements Filter
 {
-    protected $relationConstraints = [];
+    protected array $relationConstraints = [];
 
-    /** @var bool */
-    protected $addRelationConstraint = true;
-
-    public function __construct(bool $addRelationConstraint = true)
+    public function __construct(protected bool $addRelationConstraint = true)
     {
-        $this->addRelationConstraint = $addRelationConstraint;
     }
 
     /** {@inheritdoc} */
@@ -62,7 +58,7 @@ protected function isRelationProperty(Builder $query, string $property): bool
         return is_a($query->getModel()->{$firstRelationship}(), Relation::class);
     }
 
-    protected function withRelationConstraint(Builder $query, $value, string $property)
+    protected function withRelationConstraint(Builder $query, mixed $value, string $property): void
     {
         [$relation, $property] = collect(explode('.', $property))
             ->pipe(function (Collection $parts) {
diff --git a/src/Filters/FiltersPartial.php b/src/Filters/FiltersPartial.php
index 21953ac5..49b3a3ec 100644
--- a/src/Filters/FiltersPartial.php
+++ b/src/Filters/FiltersPartial.php
@@ -48,7 +48,8 @@ protected function getDatabaseDriver(Builder $query): string
         return $query->getConnection()->getDriverName();
     }
 
-    protected function getWhereRawParameters($value, string $property, string $driver): array
+  
+    protected function getWhereRawParameters(mixed $value, string $property, string $driver): array
     {
         $value = mb_strtolower((string) $value, 'UTF8');
 
diff --git a/src/Filters/FiltersScope.php b/src/Filters/FiltersScope.php
index 382dbd09..c2793dcc 100644
--- a/src/Filters/FiltersScope.php
+++ b/src/Filters/FiltersScope.php
@@ -49,7 +49,7 @@ protected function resolveParameters(Builder $query, $values, string $scope): ar
             $parameters = (new ReflectionObject($query->getModel()))
                 ->getMethod('scope' . ucfirst($scope))
                 ->getParameters();
-        } catch (ReflectionException $e) {
+        } catch (ReflectionException) {
             return $values;
         }
 
@@ -58,7 +58,8 @@ protected function resolveParameters(Builder $query, $values, string $scope): ar
                 continue;
             }
 
-            $model = $this->getClass($parameter)->newInstance();
+            /** @var TModelClass $model */
+            $model = $this->getClass($parameter)?->newInstance();
             $index = $parameter->getPosition() - 1;
             $value = $values[$index];
 
diff --git a/src/Includes/IncludeInterface.php b/src/Includes/IncludeInterface.php
index 4590621a..cca4d6dc 100644
--- a/src/Includes/IncludeInterface.php
+++ b/src/Includes/IncludeInterface.php
@@ -10,10 +10,9 @@
 interface IncludeInterface
 {
     /**
-    * @param \Illuminate\Database\Eloquent\Builder<TModelClass> $query
-    * @param string $include
-    *
-    * @return mixed
-    */
+     * @param \Illuminate\Database\Eloquent\Builder<TModelClass> $query
+     *
+     * @return mixed
+     */
     public function __invoke(Builder $query, string $include);
 }
diff --git a/src/Includes/IncludedCallback.php b/src/Includes/IncludedCallback.php
index 51e683f6..23af8e86 100644
--- a/src/Includes/IncludedCallback.php
+++ b/src/Includes/IncludedCallback.php
@@ -7,11 +7,8 @@
 
 class IncludedCallback implements IncludeInterface
 {
-    protected Closure $callback;
-
-    public function __construct(Closure $callback)
+    public function __construct(protected Closure $callback)
     {
-        $this->callback = $callback;
     }
 
     public function __invoke(Builder $query, string $relation)
diff --git a/src/Includes/IncludedRelationship.php b/src/Includes/IncludedRelationship.php
index 4ea74491..0df9e279 100644
--- a/src/Includes/IncludedRelationship.php
+++ b/src/Includes/IncludedRelationship.php
@@ -16,7 +16,7 @@ public function __invoke(Builder $query, string $relationship)
         $relatedTables = collect(explode('.', $relationship));
 
         $withs = $relatedTables
-            ->mapWithKeys(function ($table, $key) use ($query, $relatedTables) {
+            ->mapWithKeys(function ($table, $key) use ($relatedTables) {
                 $fullRelationName = $relatedTables->slice(0, $key + 1)->implode('.');
 
                 if ($this->getRequestedFieldsForRelatedTable) {
diff --git a/src/QueryBuilder.php b/src/QueryBuilder.php
index 93e9a702..80366e85 100755
--- a/src/QueryBuilder.php
+++ b/src/QueryBuilder.php
@@ -12,7 +12,6 @@
 use Spatie\QueryBuilder\Concerns\AddsIncludesToQuery;
 use Spatie\QueryBuilder\Concerns\FiltersQuery;
 use Spatie\QueryBuilder\Concerns\SortsQuery;
-use Spatie\QueryBuilder\Exceptions\InvalidSubject;
 
 /**
  * @mixin EloquentBuilder
@@ -25,46 +24,15 @@ class QueryBuilder implements ArrayAccess
     use AddsFieldsToQuery;
     use ForwardsCalls;
 
-    /** @var \Spatie\QueryBuilder\QueryBuilderRequest */
-    protected $request;
+    protected QueryBuilderRequest $request;
 
-    /** @var \Illuminate\Database\Eloquent\Builder|\Illuminate\Database\Eloquent\Relations\Relation */
-    protected $subject;
-
-    /**
-     * @param \Illuminate\Database\Eloquent\Builder|\Illuminate\Database\Eloquent\Relations\Relation $subject
-     * @param null|\Illuminate\Http\Request $request
-     */
-    public function __construct($subject, ?Request $request = null)
-    {
-        $this->initializeSubject($subject)
-            ->initializeRequest($request ?? app(Request::class));
-    }
-
-    /**
-     * @param \Illuminate\Database\Eloquent\Builder|\Illuminate\Database\Eloquent\Relations\Relation $subject
-     *
-     * @return $this
-     */
-    protected function initializeSubject($subject): static
-    {
-        throw_unless(
-            $subject instanceof EloquentBuilder || $subject instanceof Relation,
-            InvalidSubject::make($subject)
-        );
-
-        $this->subject = $subject;
-
-        return $this;
-    }
-
-    protected function initializeRequest(?Request $request = null): static
-    {
+    public function __construct(
+        protected EloquentBuilder|Relation $subject,
+        ?Request $request = null
+    ) {
         $this->request = $request
             ? QueryBuilderRequest::fromRequest($request)
             : app(QueryBuilderRequest::class);
-
-        return $this;
     }
 
     public function getEloquentBuilder(): EloquentBuilder
@@ -73,26 +41,18 @@ public function getEloquentBuilder(): EloquentBuilder
             return $this->subject;
         }
 
-        if ($this->subject instanceof Relation) {
-            return $this->subject->getQuery();
-        }
-
-        throw InvalidSubject::make($this->subject);
+        return $this->subject->getQuery();
     }
 
-    public function getSubject()
+    public function getSubject(): Relation|EloquentBuilder
     {
         return $this->subject;
     }
 
-    /**
-     * @param EloquentBuilder|Relation|string $subject
-     * @param Request|null $request
-     *
-     * @return static
-     */
-    public static function for($subject, ?Request $request = null): static
-    {
+    public static function for(
+        EloquentBuilder|Relation|string $subject,
+        ?Request $request = null
+    ): static {
         if (is_subclass_of($subject, Model::class)) {
             $subject = $subject::query();
         }
@@ -115,7 +75,7 @@ public function __call($name, $arguments)
         return $result;
     }
 
-    public function clone()
+    public function clone(): static
     {
         return clone $this;
     }
diff --git a/src/QueryBuilderRequest.php b/src/QueryBuilderRequest.php
index 2f4d999f..e2f30e14 100644
--- a/src/QueryBuilderRequest.php
+++ b/src/QueryBuilderRequest.php
@@ -8,15 +8,15 @@
 
 class QueryBuilderRequest extends Request
 {
-    private static $includesArrayValueDelimiter = ',';
+    protected static string $includesArrayValueDelimiter = ',';
 
-    private static $appendsArrayValueDelimiter = ',';
+    protected static string $appendsArrayValueDelimiter = ',';
 
-    private static $fieldsArrayValueDelimiter = ',';
+    protected static string $fieldsArrayValueDelimiter = ',';
 
-    private static $sortsArrayValueDelimiter = ',';
+    protected static string $sortsArrayValueDelimiter = ',';
 
-    private static $filterArrayValueDelimiter = ',';
+    protected static string $filterArrayValueDelimiter = ',';
 
     public static function setArrayValueDelimiter(string $delimiter): void
     {
@@ -123,12 +123,8 @@ public function filters(): Collection
         });
     }
 
-    /**
-     * @param $value
-     *
-     * @return array|bool|null
-     */
-    protected function getFilterValue($value)
+    /** @return array|float|int|string|bool|null */
+    protected function getFilterValue(mixed $value): mixed
     {
         if (empty($value)) {
             return $value;
diff --git a/src/QueryBuilderServiceProvider.php b/src/QueryBuilderServiceProvider.php
index c7e7b199..da8b9313 100644
--- a/src/QueryBuilderServiceProvider.php
+++ b/src/QueryBuilderServiceProvider.php
@@ -14,14 +14,14 @@ public function configurePackage(Package $package): void
             ->hasConfigFile();
     }
 
-    public function registeringPackage()
+    public function registeringPackage(): void
     {
         $this->app->bind(QueryBuilderRequest::class, function ($app) {
             return QueryBuilderRequest::fromRequest($app['request']);
         });
     }
 
-    public function provides()
+    public function provides(): array
     {
         return [
             QueryBuilderRequest::class,
diff --git a/tests/QueryBuilderTest.php b/tests/QueryBuilderTest.php
index f926fd71..3584dca6 100644
--- a/tests/QueryBuilderTest.php
+++ b/tests/QueryBuilderTest.php
@@ -2,8 +2,6 @@
 
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Http\Request;
-use PHPUnit\Util\Test;
-use Spatie\QueryBuilder\Exceptions\InvalidSubject;
 use Spatie\QueryBuilder\QueryBuilder;
 use Spatie\QueryBuilder\QueryBuilderRequest;
 use Spatie\QueryBuilder\Sorts\Sort;
@@ -70,17 +68,13 @@
 });
 
 it('can not be given a string that is not a class name', function () {
-    $this->expectException(InvalidSubject::class);
-
-    $this->expectExceptionMessage('Subject type `string` is invalid.');
+    $this->expectException(TypeError::class);
 
     QueryBuilder::for('not a class name');
 });
 
 it('can not be given an object that is neither relation nor eloquent builder', function () {
-    $this->expectException(InvalidSubject::class);
-
-    $this->expectExceptionMessage(sprintf('Subject class `%s` is invalid.', self::class));
+    $this->expectException(TypeError::class);
 
     QueryBuilder::for($this);
 });