diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 2c3e0d16c3..d1a31cf0bf 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -1773,6 +1773,12 @@ parameters:
 			count: 2
 			path: src/Type/UnionTypeHelper.php
 
+		-
+			rawMessage: 'Doing instanceof PHPStan\Type\Enum\EnumCaseObjectType is error-prone and deprecated. Use Type::getEnumCases() instead.'
+			identifier: phpstanApi.instanceofType
+			count: 2
+			path: src/Type/UnionTypeHelper.php
+
 		-
 			rawMessage: 'Doing instanceof PHPStan\Type\IntegerType is error-prone and deprecated. Use Type::isInteger() instead.'
 			identifier: phpstanApi.instanceofType
diff --git a/src/Type/UnionTypeHelper.php b/src/Type/UnionTypeHelper.php
index ba9eba259e..02fa454dcb 100644
--- a/src/Type/UnionTypeHelper.php
+++ b/src/Type/UnionTypeHelper.php
@@ -7,6 +7,7 @@
 use PHPStan\Type\Constant\ConstantFloatType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use function count;
 use function strcasecmp;
 use function usort;
@@ -96,6 +97,20 @@ public static function sortTypes(array $types): array
 				return self::compareStrings($a->getValue(), $b->getValue());
 			}
 
+			if ($a instanceof EnumCaseObjectType && $b instanceof EnumCaseObjectType) {
+				return self::compareStrings(
+					$a->getClassName() . '::' . $a->getEnumCaseName(),
+					$b->getClassName() . '::' . $b->getEnumCaseName(),
+				);
+			}
+
+			if (
+				($a instanceof CallableType || $a instanceof ClosureType)
+				&& ($b instanceof CallableType || $b instanceof ClosureType)
+			) {
+				return self::compareStrings($a->describe(VerbosityLevel::value()), $b->describe(VerbosityLevel::value()));
+			}
+
 			if ($a->isConstantArray()->yes() && $b->isConstantArray()->yes()) {
 				if ($a->isIterableAtLeastOnce()->no()) {
 					if ($b->isIterableAtLeastOnce()->no()) {
@@ -110,13 +125,6 @@ public static function sortTypes(array $types): array
 				return self::compareStrings($a->describe(VerbosityLevel::value()), $b->describe(VerbosityLevel::value()));
 			}
 
-			if (
-				($a instanceof CallableType || $a instanceof ClosureType)
-				&& ($b instanceof CallableType || $b instanceof ClosureType)
-			) {
-				return self::compareStrings($a->describe(VerbosityLevel::value()), $b->describe(VerbosityLevel::value()));
-			}
-
 			if ($a->isString()->yes() && $b->isString()->yes()) {
 				return self::compareStrings($a->describe(VerbosityLevel::precise()), $b->describe(VerbosityLevel::precise()));
 			}