diff --git a/components/partition_table/parttool.py b/components/partition_table/parttool.py
index fbbfc272c5..7644d06a58 100755
--- a/components/partition_table/parttool.py
+++ b/components/partition_table/parttool.py
@@ -59,7 +59,7 @@ class PartitionName(_PartitionId):
 
 class PartitionType(_PartitionId):
 
-    def __init__(self, p_type, subtype, part_list):
+    def __init__(self, p_type, subtype, part_list=None):
         _PartitionId.__init__(self, p_type=p_type, subtype=subtype, part_list=part_list)