diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09d8acf..2c2d4cc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,9 +4,11 @@ All notable changes to `phpcs-type-sniff` will be documented in this file.
 
 Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) principles.
 
-## Unreleased
+## 81.6.0 - 2024-05-23
 ### Changed
 - Min `phpcs` version to 3.10
+### Added
+- `IteratorItemTypeSniff` - enabled by default
 
 ## 81.5.2 - 2024-04-05
 ### Changed
diff --git a/README.md b/README.md
index 5b431a5..9cb76ea 100644
--- a/README.md
+++ b/README.md
@@ -331,6 +331,7 @@ String `true/false` values are automatically converted to booleans.
             <property name="FqcnMethodSniff.enabled" value="false" />
             <property name="FqcnPropSniff.enabled" value="false" />
             <property name="FqcnDescriptionSniff.enabled" value="false" />
+            <property name="IteratorItemTypeSniff.enabled" value="false" />
 
             <!-- Change violation report type for all sniffs. Default is warning. -->
             <property name="reportType" value="error" />
@@ -340,6 +341,7 @@ String `true/false` values are automatically converted to booleans.
             <property name="FqcnMethodSniff.reportType" value="error" />
             <property name="FqcnPropSniff.reportType" value="warning" />
             <property name="FqcnDescriptionSniff.reportType" value="warning" />
+            <property name="IteratorItemTypeSniff.reportType" value="warning" />
 
             <!-- Tags that should be removed from method PHPDoc -->
             <property name="FqcnMethodSniff.invalidTags" type="array">
diff --git a/src/Sniffs/CodeElement/IteratorItemTypeSniff.php b/src/Sniffs/CodeElement/IteratorItemTypeSniff.php
new file mode 100644
index 0000000..1b43c21
--- /dev/null
+++ b/src/Sniffs/CodeElement/IteratorItemTypeSniff.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace Gskema\TypeSniff\Sniffs\CodeElement;
+
+use Error;
+use Gskema\TypeSniff\Core\CodeElement\Element\AbstractFqcnElement;
+use Gskema\TypeSniff\Core\CodeElement\Element\ClassElement;
+use Gskema\TypeSniff\Core\CodeElement\Element\CodeElementInterface;
+use Gskema\TypeSniff\Core\SniffHelper;
+use IteratorAggregate;
+use PHP_CodeSniffer\Files\File;
+use ReflectionClass;
+use ReflectionException;
+
+class IteratorItemTypeSniff implements CodeElementSniffInterface
+{
+    protected const CODE = 'IteratorItemTypeSniff';
+
+    protected string $reportType = 'warning';
+    protected bool $addViolationId = true;
+
+    /**
+     * @inheritDoc
+     */
+    public function configure(array $config): void
+    {
+        $this->reportType = (string)($config['reportType'] ?? 'warning');
+        $this->addViolationId = (bool)($config['addViolationId'] ?? true);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function register(): array
+    {
+        return [
+            ClassElement::class,
+        ];
+    }
+
+    /**
+     * @inheritDoc
+     * @param AbstractFqcnElement $element
+     */
+    public function process(File $file, CodeElementInterface $element, CodeElementInterface $parentElement): void
+    {
+        try {
+            $ref = new ReflectionClass($element->getFqcn());
+        } catch (Error | ReflectionException) {
+            return; // give up...
+        }
+
+        if (!in_array(IteratorAggregate::class, $ref->getInterfaceNames())) {
+            return;
+        }
+
+        if ($element->getDocBlock()->getTagsByName('template-implements')) {
+            return;
+        } elseif ($element->getDocBlock()->getTagsByName('template-extends')) {
+            return;
+        } else {
+            $originId = $this->addViolationId ? $element->getFqcn() : null;
+            SniffHelper::addViolation(
+                $file,
+                'Classes which implement IteratorAggregate must have "@template-implements IteratorAggregate<?>"'
+                . ' doc tag with a specified item type or template type',
+                $element->getLine(),
+                static::CODE,
+                $this->reportType,
+                $originId
+            );
+        }
+    }
+}
diff --git a/src/Sniffs/CompositeCodeElementSniff.php b/src/Sniffs/CompositeCodeElementSniff.php
index 7c9462c..0a97b12 100644
--- a/src/Sniffs/CompositeCodeElementSniff.php
+++ b/src/Sniffs/CompositeCodeElementSniff.php
@@ -6,6 +6,7 @@
 use Gskema\TypeSniff\Core\CodeElement\Element\CodeElementInterface;
 use Gskema\TypeSniff\Core\CodeElement\Element\FileElement;
 use Gskema\TypeSniff\Sniffs\CodeElement\FqcnDescriptionSniff;
+use Gskema\TypeSniff\Sniffs\CodeElement\IteratorItemTypeSniff;
 use PHP_CodeSniffer\Files\File;
 use Gskema\TypeSniff\Core\CodeElement\CodeElementDetector;
 use Gskema\TypeSniff\Sniffs\CodeElement\CodeElementSniffInterface;
@@ -42,6 +43,7 @@ protected function configure(array $config): void
         $config['sniffs'][] = FqcnPropSniff::class;
         $config['sniffs'][] = FqcnConstSniff::class;
         $config['sniffs'][] = FqcnDescriptionSniff::class;
+        $config['sniffs'][] = IteratorItemTypeSniff::class;
 
         // CodeElementSniff(s) are saved by their short name, meaning you can't have 2 instances of same sniff.
         $rawSniffs = [];
diff --git a/tests/Sniffs/CompositeCodeElementSniffTest.php b/tests/Sniffs/CompositeCodeElementSniffTest.php
index ac8c3df..845b17a 100644
--- a/tests/Sniffs/CompositeCodeElementSniffTest.php
+++ b/tests/Sniffs/CompositeCodeElementSniffTest.php
@@ -566,6 +566,18 @@ public static function dataProcess(): array
             ],
         ];
 
+        // #25
+        $dataSets[] = [
+            [
+                'addViolationId' => false,
+                'useReflection' => false,
+            ],
+            __DIR__ . '/fixtures/TestIterator0.php',
+            [
+                '009 Classes which implement IteratorAggregate must have "@template-implements IteratorAggregate<?>" doc tag with a specified item type or template type'
+            ],
+        ];
+
         return $dataSets;
     }
 
diff --git a/tests/Sniffs/fixtures/TestIterator0.php b/tests/Sniffs/fixtures/TestIterator0.php
new file mode 100644
index 0000000..eb65800
--- /dev/null
+++ b/tests/Sniffs/fixtures/TestIterator0.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Gskema\TypeSniff\Sniffs\fixtures;
+
+use ArrayIterator;
+use IteratorAggregate;
+use Traversable;
+
+class TestIterator0 implements IteratorAggregate
+{
+    public function getIterator(): Traversable
+    {
+        return new ArrayIterator([]);
+    }
+}