diff --git a/backend/tests/test_assets/content/attachments.testdata.ts b/backend/tests/test_assets/content/attachments.testdata.ts
index ebe15499..6b905c0d 100644
--- a/backend/tests/test_assets/content/attachments.testdata.ts
+++ b/backend/tests/test_assets/content/attachments.testdata.ts
@@ -1,10 +1,13 @@
 import { EntityManager } from '@mikro-orm/core';
 import { Attachment } from '../../../src/entities/content/attachment.entity';
 import { testLearningObject01 } from './learning-objects.testdata';
+import { LearningObject } from '../../../src/entities/content/learning-object.entity';
 
 export function makeTestAttachments(em: EntityManager): Attachment[] {
+    const lo = em.merge(LearningObject, testLearningObject01);
+
     attachment01 = em.create(Attachment, {
-        learningObject: testLearningObject01,
+        learningObject: lo,
         name: 'attachment01',
         mimeType: '',
         content: Buffer.from(''),
diff --git a/backend/tests/test_assets/content/learning-objects.testdata.ts b/backend/tests/test_assets/content/learning-objects.testdata.ts
index 6ee3bccf..6d95b90a 100644
--- a/backend/tests/test_assets/content/learning-objects.testdata.ts
+++ b/backend/tests/test_assets/content/learning-objects.testdata.ts
@@ -75,6 +75,7 @@ export const testLearningObject02: RequiredEntityData<LearningObject> = {
     description: 'second album',
     contentType: DwengoContentType.TEXT_MARKDOWN,
     keywords: [],
+    uuid: v4(),
     teacherExclusive: false,
     skosConcepts: [],
     educationalGoals: [],
@@ -99,6 +100,7 @@ export const testLearningObject03: RequiredEntityData<LearningObject> = {
     description: 'third album',
     contentType: DwengoContentType.TEXT_MARKDOWN,
     keywords: [],
+    uuid: v4(),
     teacherExclusive: false,
     skosConcepts: [],
     educationalGoals: [],
@@ -126,6 +128,7 @@ export const testLearningObject04: RequiredEntityData<LearningObject> = {
     description: 'fifth album',
     contentType: DwengoContentType.TEXT_MARKDOWN,
     keywords: [],
+    uuid: v4(),
     teacherExclusive: false,
     skosConcepts: [],
     educationalGoals: [],
@@ -153,6 +156,7 @@ export const testLearningObject05: RequiredEntityData<LearningObject> = {
     description: 'sixth album',
     contentType: DwengoContentType.TEXT_MARKDOWN,
     keywords: [],
+    uuid: v4(),
     teacherExclusive: false,
     skosConcepts: [],
     educationalGoals: [],
@@ -173,6 +177,7 @@ export const testLearningObjectMultipleChoice: RequiredEntityData<LearningObject
     title: 'Self-evaluation',
     description: "Time to evaluate how well you understand what you've learned so far.",
     keywords: ['test'],
+    uuid: v4(),
     teacherExclusive: false,
     skosConcepts: [],
     educationalGoals: [],
@@ -199,6 +204,7 @@ export const testLearningObjectEssayQuestion: RequiredEntityData<LearningObject>
     title: 'Reflection',
     description: 'Reflect on your learning progress.',
     keywords: ['test'],
+    uuid: v4(),
     teacherExclusive: false,
     skosConcepts: [],
     educationalGoals: [],