diff --git a/tests/php/Tasks/GorriecoeMigrationTaskTest.php b/tests/php/Tasks/GorriecoeMigrationTaskTest.php
index 3a593ef1..082b53f1 100644
--- a/tests/php/Tasks/GorriecoeMigrationTaskTest.php
+++ b/tests/php/Tasks/GorriecoeMigrationTaskTest.php
@@ -319,7 +319,7 @@ public static function provideMigrateHasManyRelations(): array
     #[DataProvider('provideMigrateHasManyRelations')]
     public function testMigrateHasManyRelations(
         array $hasManyConfig,
-        string $ownerFixture = null,
+        ?string $ownerFixture = null,
         array $addColumns = []
     ): void {
         GorriecoeMigrationTask::config()->set('has_many_links_data', $hasManyConfig);