diff --git a/.github/workflows/quality.yaml b/.github/workflows/quality.yaml
index b8f4078..ad20fd5 100644
--- a/.github/workflows/quality.yaml
+++ b/.github/workflows/quality.yaml
@@ -33,5 +33,5 @@ jobs:
         uses: php-actions/phpstan@v3
         with:
           path: src/
-          level: 3
+          level: 4
           php_version: '8.2'
diff --git a/composer.lock b/composer.lock
index 2121a79..2fba402 100644
--- a/composer.lock
+++ b/composer.lock
@@ -12,12 +12,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/php-etl/bucket.git",
-                "reference": "96b2549417b603abdee3f193d7d3074c0672f45a"
+                "reference": "3e25f9ca7a85c7c05a72c004407f13da501248c0"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/php-etl/bucket/zipball/96b2549417b603abdee3f193d7d3074c0672f45a",
-                "reference": "96b2549417b603abdee3f193d7d3074c0672f45a",
+                "url": "https://api.github.com/repos/php-etl/bucket/zipball/3e25f9ca7a85c7c05a72c004407f13da501248c0",
+                "reference": "3e25f9ca7a85c7c05a72c004407f13da501248c0",
                 "shasum": ""
             },
             "require": {
@@ -61,7 +61,7 @@
                 "issues": "https://github.com/php-etl/bucket/issues",
                 "source": "https://github.com/php-etl/bucket/tree/main"
             },
-            "time": "2023-11-14T10:16:20+00:00"
+            "time": "2023-11-14T11:38:59+00:00"
         },
         {
             "name": "php-etl/bucket-contracts",
diff --git a/src/GeneratorWrapper.php b/src/GeneratorWrapper.php
index f662c69..95856f3 100644
--- a/src/GeneratorWrapper.php
+++ b/src/GeneratorWrapper.php
@@ -11,7 +11,7 @@
  */
 class GeneratorWrapper
 {
-    /** @param \Iterator<positive-int, Type> ...$iterators */
+    /** @param \Iterator<int<0, max>, Type> ...$iterators */
     public function rewind(\Iterator ...$iterators): void
     {
         foreach ($iterators as $iterator) {
@@ -19,7 +19,7 @@ public function rewind(\Iterator ...$iterators): void
         }
     }
 
-    /** @param \Iterator<positive-int, Type> ...$iterators */
+    /** @param \Iterator<int<0, max>, Type> ...$iterators */
     public function next(\Iterator ...$iterators): void
     {
         foreach ($iterators as $iterator) {
@@ -27,7 +27,7 @@ public function next(\Iterator ...$iterators): void
         }
     }
 
-    /** @param \Iterator<positive-int, Type> ...$iterators */
+    /** @param \Iterator<int<0, max>, Type> ...$iterators */
     public function valid(\Iterator ...$iterators): bool
     {
         foreach ($iterators as $iterator) {
@@ -41,7 +41,7 @@ public function valid(\Iterator ...$iterators): bool
 
     /**
      * @param Type $value
-     * @param \Generator<positive-int, ResultBucketInterface<Type>, Type, void> ...$generators
+     * @param \Generator<int<0, max>, ResultBucketInterface<Type>, Type, void> ...$generators
      */
     public function send($value, \Generator ...$generators): \Generator
     {
diff --git a/src/Loader/LogLoader.php b/src/Loader/LogLoader.php
index 02ef5c7..23fb3eb 100644
--- a/src/Loader/LogLoader.php
+++ b/src/Loader/LogLoader.php
@@ -21,7 +21,7 @@ public function __construct(private LoggerInterface $logger, private string $log
     {
     }
 
-    /** @return \Generator<positive-int, AcceptanceResultBucket<Type>|EmptyResultBucket, Type|null, void> */
+    /** @return \Generator<int<0, max>, AcceptanceResultBucket<Type>|EmptyResultBucket, Type|null, void> */
     public function load(): \Generator
     {
         $line = yield new EmptyResultBucket();
diff --git a/src/Loader/StreamLoader.php b/src/Loader/StreamLoader.php
index fd98b6e..1b3792a 100644
--- a/src/Loader/StreamLoader.php
+++ b/src/Loader/StreamLoader.php
@@ -28,7 +28,7 @@ public function __construct($stream)
         $this->stream = $stream;
     }
 
-    /** @return \Generator<positive-int, AcceptanceResultBucket<Type>|EmptyResultBucket, Type|null, void> */
+    /** @return \Generator<int<0, max>, AcceptanceResultBucket<Type>|EmptyResultBucket, Type|null, void> */
     public function load(): \Generator
     {
         $line = yield new EmptyResultBucket();
diff --git a/src/Pipeline.php b/src/Pipeline.php
index be37897..9b33007 100644
--- a/src/Pipeline.php
+++ b/src/Pipeline.php
@@ -22,9 +22,9 @@
 
 class Pipeline implements PipelineInterface, WalkableInterface, RunnableInterface
 {
-    /** @var \AppendIterator<positive-int, non-empty-array<array-key, mixed>|object, \Iterator<positive-int, non-empty-array<array-key, mixed>|object>> */
+    /** @var \AppendIterator<int<0, max>, non-empty-array<array-key, mixed>|object, \Iterator<int<0, max>, non-empty-array<array-key, mixed>|object>> */
     private readonly \AppendIterator $source;
-    /** @var \Iterator<positive-int, non-empty-array<array-key, mixed>|object>|\NoRewindIterator */
+    /** @var \Iterator<int<0, max>, non-empty-array<array-key, mixed>|object>|\NoRewindIterator */
     private iterable $subject;
 
     public function __construct(
diff --git a/src/PipelineRunner.php b/src/PipelineRunner.php
index ee57dc7..9862d08 100644
--- a/src/PipelineRunner.php
+++ b/src/PipelineRunner.php
@@ -30,11 +30,11 @@ public function __construct(
      * @template InputType of non-empty-array<array-key, mixed>|object
      * @template OutputType of non-empty-array<array-key, mixed>|object
      *
-     * @param \Iterator<positive-int, InputType|null> $source
-     * @param \Generator<positive-int, ResultBucketInterface<OutputType>|AcceptanceResultBucketInterface<InputType>|RejectionResultBucketInterface<InputType>|null, InputType, void> $coroutine
+     * @param \Iterator<int<0, max>, InputType|null> $source
+     * @param \Generator<int<0, max>, ResultBucketInterface<OutputType>|AcceptanceResultBucketInterface<InputType>|RejectionResultBucketInterface<InputType>|null, InputType, void> $coroutine
      * @param StepRejectionInterface<InputType> $rejection
      * @param StepStateInterface $state
-     * @return \Iterator<positive-int, ResultBucketInterface<OutputType>>
+     * @return \Iterator<int<0, max>, ResultBucketInterface<OutputType>>
      */
     public function run(
         \Iterator $source,
diff --git a/src/Transformer/BatchingTransformer.php b/src/Transformer/BatchingTransformer.php
index a3aa364..c404127 100644
--- a/src/Transformer/BatchingTransformer.php
+++ b/src/Transformer/BatchingTransformer.php
@@ -19,7 +19,7 @@
  */
 class BatchingTransformer implements TransformerInterface, FlushableInterface
 {
-    /** @var array<array-key, InputType> */
+    /** @var list<InputType> */
     private array $batch = [];
 
     /**
@@ -30,7 +30,7 @@ public function __construct(
     ) {
     }
 
-    /** @return \Generator<positive-int, ResultBucketInterface<OutputType>|EmptyResultBucket, InputType|null, void> */
+    /** @return \Generator<int<0, max>, ResultBucketInterface<OutputType>|EmptyResultBucket, InputType|null, void> */
     public function transform(): \Generator
     {
         $this->batch = [];
diff --git a/src/Transformer/CallableTransformer.php b/src/Transformer/CallableTransformer.php
index f7cd6ae..c3ac523 100644
--- a/src/Transformer/CallableTransformer.php
+++ b/src/Transformer/CallableTransformer.php
@@ -29,7 +29,7 @@ public function __construct(
     }
 
     /**
-     * @return \Generator<positive-int, AcceptanceResultBucket<OutputType>|EmptyResultBucket, InputType|null, void>
+     * @return \Generator<int<0, max>, AcceptanceResultBucket<OutputType>|EmptyResultBucket, InputType|null, void>
      */
     public function transform(): \Generator
     {
diff --git a/src/Transformer/ColumnTrimTransformer.php b/src/Transformer/ColumnTrimTransformer.php
index c450ffe..23b500a 100644
--- a/src/Transformer/ColumnTrimTransformer.php
+++ b/src/Transformer/ColumnTrimTransformer.php
@@ -22,7 +22,7 @@ public function __construct(
     ) {
     }
 
-    /** @return \Generator<positive-int, AcceptanceResultBucket<OutputType>|EmptyResultBucket, InputType|null, void> */
+    /** @return \Generator<int<0, max>, AcceptanceResultBucket<OutputType>|EmptyResultBucket, InputType|null, void> */
     public function transform(): \Generator
     {
         $line = yield new EmptyResultBucket();
diff --git a/src/Transformer/FilterTransformer.php b/src/Transformer/FilterTransformer.php
index a92d66e..b10c112 100644
--- a/src/Transformer/FilterTransformer.php
+++ b/src/Transformer/FilterTransformer.php
@@ -26,7 +26,7 @@ public function __construct(
     }
 
     /**
-     * @return \Generator<positive-int, AcceptanceResultBucket<Type>|EmptyResultBucket, Type|null, void>
+     * @return \Generator<int<0, max>, AcceptanceResultBucket<Type>|EmptyResultBucket, Type|null, void>
      */
     public function transform(): \Generator
     {
diff --git a/src/UnexpectedYieldedValueType.php b/src/UnexpectedYieldedValueType.php
index 0c4ad30..f4c9ba7 100644
--- a/src/UnexpectedYieldedValueType.php
+++ b/src/UnexpectedYieldedValueType.php
@@ -27,7 +27,7 @@ public function getCoroutine(): \Generator
     }
 
     /**
-     * @param \Generator<positive-int, ResultBucketInterface<OutputType>, InputType, void> $actual
+     * @param \Generator<int<0, max>, ResultBucketInterface<OutputType>, InputType, void> $actual
      * @param list<string> $expectedTypes
      * @param mixed $actual
      *