diff --git a/app/core/background/indexer_service.py b/app/core/background/indexer_service.py
index 01c28ef..36e3724 100644
--- a/app/core/background/indexer_service.py
+++ b/app/core/background/indexer_service.py
@@ -101,13 +101,16 @@ async def indexer_loop(memory, platform_found: bool, seqno: int) -> [bool, int]:
 
         session.commit()
 
-        last_known_index = session.query(StoredContent).filter(
+        last_known_index_ = session.query(StoredContent).filter(
             StoredContent.onchain_index != None
         ).order_by(StoredContent.onchain_index.desc()).first()
-        last_known_index = last_known_index.onchain_index if last_known_index else 0
+        last_known_index = last_known_index_.onchain_index if last_known_index_ else 0
         last_known_index = max(last_known_index, 0)
         make_log("Indexer", f"Last known index: {last_known_index}", level="debug")
-        next_item_index = last_known_index + 1
+        if last_known_index_:
+            next_item_index = last_known_index + 1
+        else:
+            next_item_index = 0
 
         resolve_item_result = await toncenter.run_get_method(platform.address.to_string(1, 1, 1), 'get_nft_address_by_index', [['num', next_item_index]])
         make_log("Indexer", f"Resolve item result: {resolve_item_result}", level="debug")