diff --git a/parsers/survex.py b/parsers/survex.py
index 6e918bf..d026ee2 100644
--- a/parsers/survex.py
+++ b/parsers/survex.py
@@ -607,14 +607,13 @@ class LoadingSurvex:
                         
                         for sb in chunk:
                             got_obj, created = SurvexBlock.objects.get_or_create(
-                                survexblock=sb.survexblock,
-                                defaults={'survexblockblock': sb.survexblock} # Fields to set only if creating
+                                _blockid=sb._blockid,
                             )
                             if created:
                                 print(f"  - {sb} Created", file=sys.stderr)
                             else:
                                 # update the block if it changed
-                                got_obj.block = sb.block
+                                got_obj._blockid = sb._blockid
                                 got_obj.save()
                                 # print(f"  - {sb} SAVED", file=sys.stderr)
                         print(f"  - {len(chunk)} SBs saved to db", file=sys.stderr)