diff --git a/backend/src/test/java/org/raddatz/familienarchiv/document/transcription/TranscriptionBlockMentionsRepositoryTest.java b/backend/src/test/java/org/raddatz/familienarchiv/document/transcription/TranscriptionBlockMentionsRepositoryTest.java
index 5742d654..aca4d732 100644
--- a/backend/src/test/java/org/raddatz/familienarchiv/document/transcription/TranscriptionBlockMentionsRepositoryTest.java
+++ b/backend/src/test/java/org/raddatz/familienarchiv/document/transcription/TranscriptionBlockMentionsRepositoryTest.java
@@ -12,6 +12,8 @@ import org.raddatz.familienarchiv.document.annotation.DocumentAnnotation;
 import org.raddatz.familienarchiv.document.DocumentStatus;
 import org.raddatz.familienarchiv.document.transcription.PersonMention;
 import org.raddatz.familienarchiv.document.transcription.TranscriptionBlock;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonRepository;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.jdbc.test.autoconfigure.AutoConfigureTestDatabase;
 import org.springframework.boot.data.jpa.test.autoconfigure.DataJpaTest;
@@ -30,6 +32,7 @@ class TranscriptionBlockMentionsRepositoryTest {
     @Autowired TranscriptionBlockRepository blockRepository;
     @Autowired DocumentRepository documentRepository;
     @Autowired AnnotationRepository annotationRepository;
+    @Autowired PersonRepository personRepository;
     @Autowired EntityManager em;
 
     private UUID documentId;
@@ -55,8 +58,9 @@ class TranscriptionBlockMentionsRepositoryTest {
 
     @Test
     void mentionedPersons_roundTripsTwoEntries() {
-        UUID auguste = UUID.randomUUID();
-        UUID hermann = UUID.randomUUID();
+        // person_id is a real FK since V71 — the mentioned persons must exist.
+        UUID auguste = personRepository.save(Person.builder().firstName("Auguste").lastName("Raddatz").build()).getId();
+        UUID hermann = personRepository.save(Person.builder().firstName("Hermann").lastName("Müller").build()).getId();
 
         TranscriptionBlock saved = blockRepository.saveAndFlush(TranscriptionBlock.builder()
                 .annotationId(annotationId)
@@ -97,8 +101,9 @@ class TranscriptionBlockMentionsRepositoryTest {
 
     @Test
     void findByPersonIdWithMentionsFetched_returnsOnlyBlocksReferencingPerson_withMentionsLoaded() {
-        UUID augusteId = UUID.randomUUID();
-        UUID hermannId = UUID.randomUUID();
+        // person_id is a real FK since V71 — the mentioned persons must exist.
+        UUID augusteId = personRepository.save(Person.builder().firstName("Auguste").lastName("Raddatz").build()).getId();
+        UUID hermannId = personRepository.save(Person.builder().firstName("Hermann").lastName("Müller").build()).getId();
 
         blockRepository.saveAndFlush(TranscriptionBlock.builder()
                 .annotationId(annotationId).documentId(documentId)