diff --git a/extension.neon b/extension.neon
index 7de74f0..174f4cf 100644
--- a/extension.neon
+++ b/extension.neon
@@ -19,6 +19,10 @@ services:
 		class: Nextras\OrmPhpStan\Reflection\EntityRelationshipPropertyReflectionExtension
 		tags:
 			- phpstan.broker.propertiesClassReflectionExtension
+	-
+		class: Nextras\OrmPhpStan\Reflection\EntityDateTimePropertyReflectionExtension
+		tags:
+			- phpstan.broker.propertiesClassReflectionExtension
 	-
 		class: Nextras\OrmPhpStan\Rules\SetValueMethodRule
 		tags:
diff --git a/src/Reflection/EntityDateTimePropertyReflectionExtension.php b/src/Reflection/EntityDateTimePropertyReflectionExtension.php
new file mode 100644
index 0000000..03428ef
--- /dev/null
+++ b/src/Reflection/EntityDateTimePropertyReflectionExtension.php
@@ -0,0 +1,62 @@
+<?php declare(strict_types = 1);
+
+namespace Nextras\OrmPhpStan\Reflection;
+
+use Nextras\Orm\Entity\IEntity;
+use Nextras\OrmPhpStan\Reflection\Annotations\AnnotationPropertyReflection;
+use PHPStan\Reflection\Annotations\AnnotationsPropertiesClassReflectionExtension;
+use PHPStan\Reflection\ClassReflection;
+use PHPStan\Reflection\PropertiesClassReflectionExtension;
+use PHPStan\Reflection\PropertyReflection;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\StringType;
+use PHPStan\Type\TypeCombinator;
+
+
+class EntityDateTimePropertyReflectionExtension implements PropertiesClassReflectionExtension
+{
+	/** @var AnnotationsPropertiesClassReflectionExtension */
+	private $annotationsExtension;
+
+
+	public function __construct(AnnotationsPropertiesClassReflectionExtension $annotationsExtension)
+	{
+		$this->annotationsExtension = $annotationsExtension;
+	}
+
+
+	public function hasProperty(ClassReflection $classReflection, string $propertyName): bool
+	{
+		$hasProperty = $this->annotationsExtension->hasProperty($classReflection, $propertyName);
+		if (!$hasProperty) {
+			return false;
+		}
+
+		$interfaces = array_map(function (ClassReflection $interface) {
+			return $interface->getName();
+		}, $classReflection->getInterfaces());
+		if (!in_array(IEntity::class, $interfaces, true)) {
+			return false;
+		}
+
+		$property = $this->annotationsExtension->getProperty($classReflection, $propertyName);
+		$propertyType = TypeCombinator::removeNull($property->getReadableType()); // remove null to be properly match subtype
+		$dateTimeType = new ObjectType(\DateTimeImmutable::class);
+		$hasDateTime = $dateTimeType->isSuperTypeOf($propertyType)->yes();
+
+		return $hasDateTime;
+	}
+
+
+	public function getProperty(ClassReflection $classReflection, string $propertyName): PropertyReflection
+	{
+		$property = $this->annotationsExtension->getProperty($classReflection, $propertyName);
+		return new AnnotationPropertyReflection(
+			$property->getDeclaringClass(),
+			$property->getReadableType(),
+			TypeCombinator::union($property->getWritableType(), new StringType()),
+			$property->isReadable(),
+			$property->isWritable()
+		);
+	}
+}
diff --git a/tests/expected.txt b/tests/expected.txt
index ca754bc..abd463d 100644
--- a/tests/expected.txt
+++ b/tests/expected.txt
@@ -1,11 +1,12 @@
 /testbox/Rules/Test.php:21:Entity NextrasTests\OrmPhpStan\Rules\Entity: property $age (int) does not accept string.
 /testbox/Rules/Test.php:22:Entity NextrasTests\OrmPhpStan\Rules\Entity: property $description (string) does not accept int.
-/testbox/Rules/Test.php:23:Entity NextrasTests\OrmPhpStan\Rules\Entity: property $createdAt (DateTimeImmutable) does not accept DateTime.
+/testbox/Rules/Test.php:23:Entity NextrasTests\OrmPhpStan\Rules\Entity: property $createdAt (DateTimeImmutable|string) does not accept DateTime.
 /testbox/Rules/Test.php:24:Entity NextrasTests\OrmPhpStan\Rules\Entity has no $foo property.
 /testbox/Rules/Test.php:25:Entity NextrasTests\OrmPhpStan\Rules\Entity: property $read is read-only.
 /testbox/Rules/Test.php:26:Entity NextrasTests\OrmPhpStan\Rules\Entity: property $age (int) does not accept string.
 /testbox/Types/CollectionTypesTest.php:15:Parameter #1 $author of method NextrasTests\OrmPhpStan\Types\CollectionTypesTest::takeAuthor() expects NextrasTests\OrmPhpStan\Types\Author, NextrasTests\OrmPhpStan\Types\Author|null given.
 /testbox/Types/CollectionTypesTest.php:16:Parameter #1 $author of method NextrasTests\OrmPhpStan\Types\CollectionTypesTest::takeAuthor() expects NextrasTests\OrmPhpStan\Types\Author, NextrasTests\OrmPhpStan\Types\Author|null given.
+/testbox/Types/DateTimePropertyTypesTest.php:9:Property NextrasTests\OrmPhpStan\Types\Book::$date (DateTimeImmutable|string|null) does not accept int.
 /testbox/Types/RelationshipPropertyTypesTest.php:11:Parameter #1 $int of method NextrasTests\OrmPhpStan\Types\RelationshipPropertyTypesTest::takeInt() expects int, NextrasTests\OrmPhpStan\Types\Author given.
 /testbox/Types/RelationshipPropertyTypesTest.php:13:Parameter #1 $int of method NextrasTests\OrmPhpStan\Types\RelationshipPropertyTypesTest::takeInt() expects int, NextrasTests\OrmPhpStan\Types\Author given.
 /testbox/Types/RelationshipPropertyTypesTest.php:14:Property NextrasTests\OrmPhpStan\Types\Book::$author (int|NextrasTests\OrmPhpStan\Types\Author) does not accept NextrasTests\OrmPhpStan\Types\Book.
diff --git a/tests/testbox/Types/DateTimePropertyTypesTest.php b/tests/testbox/Types/DateTimePropertyTypesTest.php
new file mode 100644
index 0000000..c5cc11e
--- /dev/null
+++ b/tests/testbox/Types/DateTimePropertyTypesTest.php
@@ -0,0 +1,24 @@
+<?php declare(strict_types = 1);
+
+namespace NextrasTests\OrmPhpStan\Types;
+
+class DateTimePropertyTypesTest
+{
+	public function testError(Book $book): void
+	{
+		$book->date = 1;
+	}
+
+
+	public function testOk(Book $book): void
+	{
+		$book->date = 'now';
+		$this->takeNullableDateTime($book->date);
+		$book->date = null;
+	}
+
+
+	private function takeNullableDateTime(?\DateTimeImmutable $data): void
+	{
+	}
+}
diff --git a/tests/testbox/Types/fixtures/Book.php b/tests/testbox/Types/fixtures/Book.php
index cfde1d9..fcf9c5f 100644
--- a/tests/testbox/Types/fixtures/Book.php
+++ b/tests/testbox/Types/fixtures/Book.php
@@ -4,6 +4,7 @@
 
 /**
  * @property Author $author {m:1 Author::$books}
+ * @property \DateTimeImmutable|null $date
  */
 class Book extends \Nextras\Orm\Entity\Entity
 {