diff --git a/src/Type/Php/SimpleXMLElementClassPropertyReflectionExtension.php b/src/Type/Php/SimpleXMLElementClassPropertyReflectionExtension.php
index 9646898c00..503e998fd3 100644
--- a/src/Type/Php/SimpleXMLElementClassPropertyReflectionExtension.php
+++ b/src/Type/Php/SimpleXMLElementClassPropertyReflectionExtension.php
@@ -6,6 +6,8 @@
 use PHPStan\Reflection\Php\SimpleXMLElementProperty;
 use PHPStan\Reflection\PropertiesClassReflectionExtension;
 use PHPStan\Reflection\PropertyReflection;
+use PHPStan\Type\BenevolentUnionType;
+use PHPStan\Type\NullType;
 use PHPStan\Type\ObjectType;
 
 class SimpleXMLElementClassPropertyReflectionExtension implements PropertiesClassReflectionExtension
@@ -19,7 +21,7 @@ public function hasProperty(ClassReflection $classReflection, string $propertyNa
 
 	public function getProperty(ClassReflection $classReflection, string $propertyName): PropertyReflection
 	{
-		return new SimpleXMLElementProperty($classReflection, new ObjectType($classReflection->getName()));
+		return new SimpleXMLElementProperty($classReflection, new BenevolentUnionType([new ObjectType($classReflection->getName()), new NullType()]));
 	}
 
 }
diff --git a/tests/PHPStan/Rules/Classes/data/impossible-instanceof.php b/tests/PHPStan/Rules/Classes/data/impossible-instanceof.php
index 106781de88..a11d9a1c4e 100644
--- a/tests/PHPStan/Rules/Classes/data/impossible-instanceof.php
+++ b/tests/PHPStan/Rules/Classes/data/impossible-instanceof.php
@@ -441,3 +441,13 @@ function test(\DateTimeInterface $a, \DateTimeInterface $b): void {
 		if ($b instanceof $a) return;
 	}
 }
+
+class InstanceofBenevolentUnionType
+{
+	public function doFoo(\SimpleXMLElement $xml)
+	{
+		echo $xml->branch1 instanceof \SimpleXMLElement;
+		echo $xml->branch2->branch3 instanceof \SimpleXMLElement;
+	}
+
+}