diff --git a/packages/TypeDeclaration/src/Rector/FunctionLike/ReturnTypeDeclarationRector.php b/packages/TypeDeclaration/src/Rector/FunctionLike/ReturnTypeDeclarationRector.php
index 8ceda80efe1b..f1a615730532 100644
--- a/packages/TypeDeclaration/src/Rector/FunctionLike/ReturnTypeDeclarationRector.php
+++ b/packages/TypeDeclaration/src/Rector/FunctionLike/ReturnTypeDeclarationRector.php
@@ -2,12 +2,18 @@
 
 namespace Rector\TypeDeclaration\Rector\FunctionLike;
 
+use Iterator;
 use PhpParser\Node;
 use PhpParser\Node\Stmt\ClassLike;
 use PhpParser\Node\Stmt\ClassMethod;
 use PhpParser\Node\Stmt\Function_;
+use PHPStan\Type\ArrayType;
+use PHPStan\Type\IntersectionType;
+use PHPStan\Type\IterableType;
 use PHPStan\Type\MixedType;
+use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
+use PHPStan\Type\UnionType;
 use Rector\Exception\ShouldNotHappenException;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 use Rector\RectorDefinition\CodeSample;
@@ -230,7 +236,12 @@ private function isReturnTypeAlreadyAdded(Node $node, Type $returnType): bool
             return false;
         }
 
-        if ($this->print($node->returnType) === $this->print($returnNode)) {
+        if ($this->areNodesEqual($node->returnType, $returnNode)) {
+            return true;
+        }
+
+        // is array <=> iterable <=> Iterator co-type? → skip
+        if ($this->isArrayIterableIteratorCoType($node, $returnType)) {
             return true;
         }
 
@@ -244,4 +255,42 @@ private function isReturnTypeAlreadyAdded(Node $node, Type $returnType): bool
 
         return false;
     }
+
+    private function isStaticTypeIterable(Type $type): bool
+    {
+        if ($type instanceof ArrayType) {
+            return true;
+        }
+
+        if ($type instanceof IterableType) {
+            return true;
+        }
+
+        if ($type instanceof ObjectType) {
+            if ($type->getClassName() === Iterator::class) {
+                return true;
+            }
+        }
+
+        if ($type instanceof UnionType || $type instanceof IntersectionType) {
+            foreach ($type->getTypes() as $joinedType) {
+                if (! $this->isStaticTypeIterable($joinedType)) {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+
+    private function isArrayIterableIteratorCoType(Node $node, Type $returnType): bool
+    {
+        if (! $this->isNames($node->returnType, ['iterable', 'Iterator', 'array'])) {
+            return false;
+        }
+
+        return $this->isStaticTypeIterable($returnType);
+    }
 }
diff --git a/packages/TypeDeclaration/tests/Rector/FunctionLike/ReturnTypeDeclarationRector/Fixture/skip_iterable_array_iterator_co_type.php.inc b/packages/TypeDeclaration/tests/Rector/FunctionLike/ReturnTypeDeclarationRector/Fixture/skip_iterable_array_iterator_co_type.php.inc
new file mode 100644
index 000000000000..1288763c3844
--- /dev/null
+++ b/packages/TypeDeclaration/tests/Rector/FunctionLike/ReturnTypeDeclarationRector/Fixture/skip_iterable_array_iterator_co_type.php.inc
@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\TypeDeclaration\Tests\Rector\ClassMethod\ReturnTypeDeclarationRector\Fixture;
+
+use Iterator;
+
+class SkipIterableArrayIteratorCoType
+{
+    public function run(): Iterator
+    {
+        yield 5;
+    }
+}
diff --git a/packages/TypeDeclaration/tests/Rector/FunctionLike/ReturnTypeDeclarationRector/ReturnTypeDeclarationRectorTest.php b/packages/TypeDeclaration/tests/Rector/FunctionLike/ReturnTypeDeclarationRector/ReturnTypeDeclarationRectorTest.php
index baef4aded0de..75a207b3cbcb 100644
--- a/packages/TypeDeclaration/tests/Rector/FunctionLike/ReturnTypeDeclarationRector/ReturnTypeDeclarationRectorTest.php
+++ b/packages/TypeDeclaration/tests/Rector/FunctionLike/ReturnTypeDeclarationRector/ReturnTypeDeclarationRectorTest.php
@@ -60,6 +60,8 @@ public function provideDataForTests(): Iterator
         yield [__DIR__ . '/Fixture/dunglas/nullable_types.php.inc'];
         // anonymous class
         yield [__DIR__ . '/Fixture/a_new_class.php.inc'];
+
+        yield [__DIR__ . '/Fixture/skip_iterable_array_iterator_co_type.php.inc'];
     }
 
     protected function getRectorClass(): string