diff --git a/packages/mimir/test/utils.dart b/packages/mimir/test/utils.dart
index b6a06c9..cab2523 100644
--- a/packages/mimir/test/utils.dart
+++ b/packages/mimir/test/utils.dart
@@ -33,7 +33,7 @@ List<Map<String, dynamic>> useExercises() {
 }
 
 @freezed
-class ComparableMimirIndexSettings with _$ComparableMimirIndexSettings {
+sealed class ComparableMimirIndexSettings with _$ComparableMimirIndexSettings {
   const factory ComparableMimirIndexSettings({
     required Set<String>? searchableFields,
     required Set<String> filterableFields,