diff --git a/src/Type/TypeCombinator.php b/src/Type/TypeCombinator.php
index 5159711e6f..b1060af54c 100644
--- a/src/Type/TypeCombinator.php
+++ b/src/Type/TypeCombinator.php
@@ -16,7 +16,6 @@
 use PHPStan\Type\Constant\ConstantFloatType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
-use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\GenericClassStringType;
 use PHPStan\Type\Generic\TemplateArrayType;
 use PHPStan\Type\Generic\TemplateBenevolentUnionType;
@@ -201,7 +200,8 @@ public static function union(Type ...$types): Type
 			if ($types[$i] instanceof StringType && !$types[$i] instanceof ClassStringType) {
 				$hasGenericScalarTypes[ConstantStringType::class] = true;
 			}
-			if ($types[$i] instanceof EnumCaseObjectType) {
+			$enumCases = $types[$i]->getEnumCases();
+			if (count($enumCases) === 1) {
 				$enumCaseTypes[$types[$i]->describe(VerbosityLevel::cache())] = $types[$i];
 
 				unset($types[$i]);