diff --git a/src/fragmentarium/application/FragmentService.test.ts b/src/fragmentarium/application/FragmentService.test.ts
index 4b2e834dd..fd5cb4ae3 100644
--- a/src/fragmentarium/application/FragmentService.test.ts
+++ b/src/fragmentarium/application/FragmentService.test.ts
@@ -115,6 +115,13 @@ const testData: TestData<FragmentService>[] = [
   new TestData('findPhoto', [fragment], imageRepository.findPhoto, resultStub, [
     fragment.number,
   ]),
+  new TestData(
+    'findThumbnail',
+    [fragment, 'small'],
+    imageRepository.findThumbnail,
+    resultStub,
+    [fragment.number, 'small']
+  ),
   new TestData(
     'folioPager',
     [folio, 'K.1'],