diff --git a/src/PHPStanStaticTypeMapper/TypeAnalyzer/UnionTypeAnalyzer.php b/src/PHPStanStaticTypeMapper/TypeAnalyzer/UnionTypeAnalyzer.php
index be19eaba320..e1f2f4ca875 100644
--- a/src/PHPStanStaticTypeMapper/TypeAnalyzer/UnionTypeAnalyzer.php
+++ b/src/PHPStanStaticTypeMapper/TypeAnalyzer/UnionTypeAnalyzer.php
@@ -4,25 +4,13 @@
 
 namespace Rector\PHPStanStaticTypeMapper\TypeAnalyzer;
 
-use PHPStan\Type\NullType;
+use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\UnionType;
 
 final class UnionTypeAnalyzer
 {
-    public function isNullable(UnionType $unionType, bool $checkTwoTypes = false): bool
+    public function isNullable(UnionType $unionType): bool
     {
-        $types = $unionType->getTypes();
-
-        if ($checkTwoTypes && count($types) > 2) {
-            return false;
-        }
-
-        foreach ($types as $type) {
-            if ($type instanceof NullType) {
-                return true;
-            }
-        }
-
-        return false;
+        return TypeCombinator::containsNull($unionType);
     }
 }