diff --git a/tests/PHPStan/Type/TypeCombinatorTest.php b/tests/PHPStan/Type/TypeCombinatorTest.php
index 84e3c7f3976..31e3c8f03a8 100644
--- a/tests/PHPStan/Type/TypeCombinatorTest.php
+++ b/tests/PHPStan/Type/TypeCombinatorTest.php
@@ -894,6 +894,14 @@ public function dataUnion(): iterable
 				UnionType::class,
 				'(1|2)|string',
 			],
+			[
+				[
+					new BenevolentUnionType([new ConstantStringType('1'), new ConstantStringType('2')]),
+					new StringType(),
+				],
+				StringType::class,
+				'string',
+			],
 			[
 				[
 					new BenevolentUnionType([new ConstantIntegerType(1), new ConstantIntegerType(2), new ConstantIntegerType(3)]),