diff --git a/apps/sam/services.py b/apps/sam/services.py
index 65ce2b01..b577991e 100644
--- a/apps/sam/services.py
+++ b/apps/sam/services.py
@@ -1,6 +1,6 @@
 from apps.sam.models import Order, OrderItem
 from rest_framework.exceptions import ValidationError
-from django.db.models import F
+from django.db.models import F, Sum
 from apps.inm.models import MIO, MIOItem