diff --git a/packages/Doctrine/tests/Rector/Property/AddUuidAnnotationsToIdPropertyRector/Fixture/fixture.php.inc b/packages/Doctrine/tests/Rector/Property/AddUuidAnnotationsToIdPropertyRector/Fixture/fixture.php.inc
index 1d6b1b94a74c..363f13a056a2 100644
--- a/packages/Doctrine/tests/Rector/Property/AddUuidAnnotationsToIdPropertyRector/Fixture/fixture.php.inc
+++ b/packages/Doctrine/tests/Rector/Property/AddUuidAnnotationsToIdPropertyRector/Fixture/fixture.php.inc
@@ -37,10 +37,10 @@ use JMS\Serializer\Annotation as Serializer;
 class SomeFixture
 {
     /**
+     * @var \Ramsey\Uuid\UuidInterface
      * @ORM\Id
      * @ORM\Column(type="uuid_binary")
      * @Serializer\Type("string")
-     * @var \Ramsey\Uuid\UuidInterface
      */
     private $id;
 }
diff --git a/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockClassRenamer.php b/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockClassRenamer.php
index 045a44a54c5c..c4e22fb1fecd 100644
--- a/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockClassRenamer.php
+++ b/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockClassRenamer.php
@@ -10,7 +10,6 @@
 use PHPStan\PhpDocParser\Ast\Type\IdentifierTypeNode;
 use PHPStan\Type\Type;
 use Rector\BetterPhpDocParser\Ast\PhpDocNodeTraverser;
-use Rector\Exception\ShouldNotHappenException;
 use Rector\NodeTypeResolver\StaticTypeMapper;
 
 final class DocBlockClassRenamer
@@ -54,14 +53,9 @@ function (PhpDocParserNode $node) use ($phpParserNode, $oldType, $newType): PhpD
                     return $node;
                 }
 
-                $newIdentifierType = $this->staticTypeMapper->mapPHPStanTypeToPHPStanPhpDocTypeNode($newType);
-                if ($newIdentifierType === null) {
-                    throw new ShouldNotHappenException();
-                }
-
                 $this->hasNodeChanged = true;
 
-                return $newIdentifierType;
+                return $this->staticTypeMapper->mapPHPStanTypeToPHPStanPhpDocTypeNode($newType);
             }
         );
 
diff --git a/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockManipulator.php b/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockManipulator.php
index a6b94bcdee85..edaef744fe76 100644
--- a/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockManipulator.php
+++ b/packages/NodeTypeResolver/src/PhpDoc/NodeAnalyzer/DocBlockManipulator.php
@@ -16,6 +16,7 @@
 use PHPStan\PhpDocParser\Ast\PhpDoc\PhpDocNode;
 use PHPStan\PhpDocParser\Ast\PhpDoc\PhpDocTagNode;
 use PHPStan\PhpDocParser\Ast\PhpDoc\PhpDocTagValueNode;
+use PHPStan\PhpDocParser\Ast\PhpDoc\VarTagValueNode;
 use PHPStan\PhpDocParser\Ast\Type\IdentifierTypeNode;
 use PHPStan\Type\ArrayType;
 use PHPStan\Type\Constant\ConstantArrayType;
@@ -256,8 +257,22 @@ public function changeVarTag(Node $node, Type $newType): void
             }
         }
 
-        $this->removeTagFromNode($node, 'var', true);
-        $this->addTypeSpecificTag($node, 'var', $newType);
+        if ($this->hasTag($node, '@var')) {
+            // just change the type
+            $varTag = $this->getTagByName($node, '@var');
+
+            /** @var VarTagValueNode $varTagValueNode */
+            $varTagValueNode = $varTag->value;
+
+            $phpDocType = $this->staticTypeMapper->mapPHPStanTypeToPHPStanPhpDocTypeNode($newType);
+            $varTagValueNode->type = $phpDocType;
+
+            // update doc :)
+            $phpDocInfo = $this->createPhpDocInfoFromNode($node);
+            $this->updateNodeWithPhpDocInfo($node, $phpDocInfo);
+        } else {
+            $this->addTypeSpecificTag($node, 'var', $newType);
+        }
 
         // to invoke the node override
         $node->setAttribute(AttributeKey::ORIGINAL_NODE, null);
diff --git a/packages/NodeTypeResolver/src/StaticTypeMapper.php b/packages/NodeTypeResolver/src/StaticTypeMapper.php
index 4e659aaac79d..4235291d5f73 100644
--- a/packages/NodeTypeResolver/src/StaticTypeMapper.php
+++ b/packages/NodeTypeResolver/src/StaticTypeMapper.php
@@ -91,7 +91,7 @@ public function __construct(
         $this->objectTypeSpecifier = $objectTypeSpecifier;
     }
 
-    public function mapPHPStanTypeToPHPStanPhpDocTypeNode(Type $phpStanType): ?TypeNode
+    public function mapPHPStanTypeToPHPStanPhpDocTypeNode(Type $phpStanType): TypeNode
     {
         if ($phpStanType instanceof UnionType) {
             $unionTypesNodes = [];
@@ -104,10 +104,6 @@ public function mapPHPStanTypeToPHPStanPhpDocTypeNode(Type $phpStanType): ?TypeN
 
         if ($phpStanType instanceof ArrayType) {
             $itemTypeNode = $this->mapPHPStanTypeToPHPStanPhpDocTypeNode($phpStanType->getItemType());
-            if ($itemTypeNode === null) {
-                throw new ShouldNotHappenException();
-            }
-
             return new ArrayTypeNode($itemTypeNode);
         }
 
diff --git a/packages/TypeDeclaration/tests/Rector/Property/CompleteVarDocTypePropertyRector/CompleteVarDocTypePropertyRectorTest.php b/packages/TypeDeclaration/tests/Rector/Property/CompleteVarDocTypePropertyRector/CompleteVarDocTypePropertyRectorTest.php
index 1dfa134f7262..2701a80bd39c 100644
--- a/packages/TypeDeclaration/tests/Rector/Property/CompleteVarDocTypePropertyRector/CompleteVarDocTypePropertyRectorTest.php
+++ b/packages/TypeDeclaration/tests/Rector/Property/CompleteVarDocTypePropertyRector/CompleteVarDocTypePropertyRectorTest.php
@@ -20,6 +20,7 @@ public function test(string $file): void
 
     public function provideDataForTest(): Iterator
     {
+        yield [__DIR__ . '/Fixture/keep_comment.php.inc'];
         yield [__DIR__ . '/Fixture/property_assign.php.inc'];
         yield [__DIR__ . '/Fixture/default_value.php.inc'];
         yield [__DIR__ . '/Fixture/assign_conflict.php.inc'];
diff --git a/packages/TypeDeclaration/tests/Rector/Property/CompleteVarDocTypePropertyRector/Fixture/keep_comment.php.inc b/packages/TypeDeclaration/tests/Rector/Property/CompleteVarDocTypePropertyRector/Fixture/keep_comment.php.inc
new file mode 100644
index 000000000000..81ea7e6aaa17
--- /dev/null
+++ b/packages/TypeDeclaration/tests/Rector/Property/CompleteVarDocTypePropertyRector/Fixture/keep_comment.php.inc
@@ -0,0 +1,43 @@
+<?php
+
+namespace Rector\TypeDeclaration\Tests\Rector\Property\CompleteVarDocTypePropertyRector\Fixture;
+
+class KeepComment
+{
+    /**
+     * @var string e.g. 123
+     */
+    private $ids;
+
+    public function setIds()
+    {
+        $this->ids[] = 'hello';
+        if (random_int(1, 100)) {
+            $this->ids = 'hey';
+        }
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\TypeDeclaration\Tests\Rector\Property\CompleteVarDocTypePropertyRector\Fixture;
+
+class KeepComment
+{
+    /**
+     * @var string[]|string e.g. 123
+     */
+    private $ids;
+
+    public function setIds()
+    {
+        $this->ids[] = 'hello';
+        if (random_int(1, 100)) {
+            $this->ids = 'hey';
+        }
+    }
+}
+
+?>