diff --git a/backend/src/main/java/org/raddatz/familienarchiv/service/TranscriptionService.java b/backend/src/main/java/org/raddatz/familienarchiv/service/TranscriptionService.java
index 69982788..bfb02253 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/service/TranscriptionService.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/service/TranscriptionService.java
@@ -104,8 +104,8 @@ public class TranscriptionService {
     public TranscriptionBlock upsertGuidedBlock(UUID documentId, UUID annotationId,
                                                  String text, UUID userId) {
         return blockRepository.findByAnnotationId(annotationId).map(existing -> {
-            if (existing.getSource() == BlockSource.MANUAL) {
-                return existing; // never overwrite manual transcription
+            if (existing.getSource() == BlockSource.MANUAL && !existing.getText().isBlank()) {
+                return existing; // never overwrite non-empty manual transcription
             }
             existing.setText(sanitizeText(text));
             existing.setUpdatedBy(userId);
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/service/TranscriptionServiceGuidedTest.java b/backend/src/test/java/org/raddatz/familienarchiv/service/TranscriptionServiceGuidedTest.java
index afbc90bf..e8d53cad 100644
--- a/backend/src/test/java/org/raddatz/familienarchiv/service/TranscriptionServiceGuidedTest.java
+++ b/backend/src/test/java/org/raddatz/familienarchiv/service/TranscriptionServiceGuidedTest.java
@@ -74,7 +74,7 @@ class TranscriptionServiceGuidedTest {
     }
 
     @Test
-    void upsertGuidedBlock_doesNotOverwriteManualBlock() {
+    void upsertGuidedBlock_doesNotOverwriteNonEmptyManualBlock() {
         TranscriptionBlock manual = TranscriptionBlock.builder()
                 .id(UUID.randomUUID())
                 .annotationId(annId)
@@ -90,4 +90,22 @@ class TranscriptionServiceGuidedTest {
         assertThat(result.getText()).isEqualTo("manually written");
         verify(blockRepository, never()).save(any());
     }
+
+    @Test
+    void upsertGuidedBlock_fillsEmptyManualBlock_withOcrText() {
+        TranscriptionBlock emptyManual = TranscriptionBlock.builder()
+                .id(UUID.randomUUID())
+                .annotationId(annId)
+                .documentId(docId)
+                .text("")
+                .source(BlockSource.MANUAL)
+                .sortOrder(0)
+                .build();
+        when(blockRepository.findByAnnotationId(annId)).thenReturn(Optional.of(emptyManual));
+
+        TranscriptionBlock result = service.upsertGuidedBlock(docId, annId, "ocr result", userId);
+
+        assertThat(result.getText()).isEqualTo("ocr result");
+        verify(blockRepository).save(any());
+    }
 }