diff --git a/backend/app/services/importer.py b/backend/app/services/importer.py
index ccfef94..5634928 100644
--- a/backend/app/services/importer.py
+++ b/backend/app/services/importer.py
@@ -534,7 +534,9 @@ class Importer:
         # branches stay untouched. NULL-only so a re-extract never re-stamps and
         # the backfill (reextract task → this same path) is idempotent. Nested
         # members link to this OUTER archive — the only one stored as a blob.
-        self._stamp_member_archive(post.id, source, member_record_ids)
+        self._stamp_member_archive(
+            post.id if post is not None else None, source, member_record_ids,
+        )
         if member_ids:
             return ImportResult(
                 status="imported", image_id=member_ids[0],