diff --git a/backend/app/services/imports/archidekt.py b/backend/app/services/imports/archidekt.py
index 4582db7..7286545 100644
--- a/backend/app/services/imports/archidekt.py
+++ b/backend/app/services/imports/archidekt.py
@@ -121,7 +121,7 @@ def _parse_json(text: str) -> list[RawCardRow]:
 
         set_obj = card.get("set") or {}
         set_code = (
-            set_obj.get("code") if isinstance(set_obj, dict) else str(set_obj)
+            (set_obj.get("code") if isinstance(set_obj, dict) else str(set_obj)) or ""
         ).lower().strip()
 
         collector = str(card.get("collectorNumber") or card.get("collector_number") or "").strip()