diff --git a/Modules/Quotas/test/Quotas.Application.Tests/Tests/Identities/QuotaCreatedForTierIntegrationEventHandlerTests.cs b/Modules/Quotas/test/Quotas.Application.Tests/Tests/Identities/QuotaCreatedForTierIntegrationEventHandlerTests.cs
index 6c61b42766..360c92b799 100644
--- a/Modules/Quotas/test/Quotas.Application.Tests/Tests/Identities/QuotaCreatedForTierIntegrationEventHandlerTests.cs
+++ b/Modules/Quotas/test/Quotas.Application.Tests/Tests/Identities/QuotaCreatedForTierIntegrationEventHandlerTests.cs
@@ -68,7 +68,7 @@ public async void Updates_metric_statuses_after_creating_tier_quota()
         ).MustHaveHappened();
     }
 
-    private static QuotaCreatedForTierIntegrationEventHandler CreateHandler(IIdentitiesRepository identities, ITiersRepository tierQuotaDefinitions, IMetricStatusesService metricStatusesService = null)
+    private static QuotaCreatedForTierIntegrationEventHandler CreateHandler(IIdentitiesRepository identities, ITiersRepository tierQuotaDefinitions, IMetricStatusesService? metricStatusesService = null)
     {
         var logger = A.Fake<ILogger<QuotaCreatedForTierIntegrationEventHandler>>();
         return new QuotaCreatedForTierIntegrationEventHandler(identities, tierQuotaDefinitions, logger, metricStatusesService ?? A.Fake<IMetricStatusesService>());