diff --git a/management/commands/_import_utils.py b/management/commands/_import_utils.py
index eb9c8b5..76552a7 100644
--- a/management/commands/_import_utils.py
+++ b/management/commands/_import_utils.py
@@ -5,7 +5,6 @@ import time
 from collections import defaultdict
 
 from django.core.management.base import BaseCommand
-from collections import defaultdict
 from django.apps import apps
 from django.db import transaction
 
@@ -61,8 +60,8 @@ class ImportCommand(BaseCommand):
             json.dump(self.MAP_IDBDE, fp, sort_keys=True, indent=2)
 
     def load_map(self, filename):
-        with open(filename, 'w') as fp:
-            self.MAP_IDBDE = json.load(fp)
+        with open(filename, 'r') as fp:
+            self.MAP_IDBDE = json.load(fp, object_hook=lambda d: {int(k): int(v) for k, v in d.items()})
 
 
 class BulkCreateManager(object):