diff --git a/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart b/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart
index f827a65..3df4a70 100644
--- a/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart
+++ b/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart
@@ -176,7 +176,7 @@ class AvailabilityViewModel {
     );
     return AvailabilityModel(
       id: ids?.firstOrNull,
-      userId: userId!,
+      userId: userId ?? "",
       startDate: startDate,
       endDate: endDate,
       breaks: breaks.map((e) => e.toBreak()).toList(),