diff --git a/backend/local_rag.py b/backend/local_rag.py
index 1aac605..437d32f 100644
--- a/backend/local_rag.py
+++ b/backend/local_rag.py
@@ -540,7 +540,7 @@ async def _ensure_prepare_job(slug: str) -> Optional[str]:
 
         if not payload["states"].get("has_files") or not pending_signature:
             return None
-        if payload["states"].get("is_indexed") and payload.get("source_signature") == pending_signature:
+        if payload["states"].get("is_indexed") and payload.get("prepare_signature") == pending_signature:
             _clear_pending_prepare(slug)
             return None
 
@@ -563,7 +563,7 @@ async def _handle_post_job_state(slug: str, job_type: str, status: str) -> None:
         return
 
     if payload["states"].get("is_indexed") and (
-        pending_signature is None or payload.get("source_signature") == pending_signature
+        pending_signature is None or payload.get("prepare_signature") == pending_signature
     ):
         _mark_all_files_ready(slug)
         _clear_pending_prepare(slug)