diff --git a/backend/src/main/resources/db/migration/V28__add_unique_constraint_ocr_job_documents.sql b/backend/src/main/resources/db/migration/V28__add_unique_constraint_ocr_job_documents.sql
new file mode 100644
index 00000000..8b476381
--- /dev/null
+++ b/backend/src/main/resources/db/migration/V28__add_unique_constraint_ocr_job_documents.sql
@@ -0,0 +1,2 @@
+ALTER TABLE ocr_job_documents
+    ADD CONSTRAINT uq_ocr_job_document UNIQUE (job_id, document_id);