diff --git a/InvenTree/order/serializers.py b/InvenTree/order/serializers.py
index bc3d72e739..821e8bf343 100644
--- a/InvenTree/order/serializers.py
+++ b/InvenTree/order/serializers.py
@@ -112,8 +112,9 @@ class POLineItemSerializer(InvenTreeModelSerializer):
             self.fields.pop('part_detail')
             self.fields.pop('supplier_part_detail')
 
-    quantity = serializers.FloatField()
-    received = serializers.FloatField()
+    # TODO: Once https://github.com/inventree/InvenTree/issues/1687 is fixed, remove default values
+    quantity = serializers.FloatField(default=1)
+    received = serializers.FloatField(default=0)
 
     part_detail = PartBriefSerializer(source='get_base_part', many=False, read_only=True)
     supplier_part_detail = SupplierPartSerializer(source='part', many=False, read_only=True)
@@ -316,7 +317,9 @@ class SOLineItemSerializer(InvenTreeModelSerializer):
     part_detail = PartBriefSerializer(source='part', many=False, read_only=True)
     allocations = SalesOrderAllocationSerializer(many=True, read_only=True)
 
-    quantity = serializers.FloatField()
+    # TODO: Once https://github.com/inventree/InvenTree/issues/1687 is fixed, remove default values
+    quantity = serializers.FloatField(default=1)
+
     allocated = serializers.FloatField(source='allocated_quantity', read_only=True)
     fulfilled = serializers.FloatField(source='fulfilled_quantity', read_only=True)
     sale_price_string = serializers.CharField(source='sale_price', read_only=True)