diff --git a/yuthon_approval/models/inherit_approval_category.py b/yuthon_approval/models/inherit_approval_category.py
index 45f3fb53a..e25685daf 100644
--- a/yuthon_approval/models/inherit_approval_category.py
+++ b/yuthon_approval/models/inherit_approval_category.py
@@ -19,7 +19,7 @@ class ApprovalCategory(models.Model):
         for record in self:
             category_approver = []
             record.approver_ids = None
-            for user in list(set(record.approval_process_ids._create_users())):
+            for user in list(set(record.approval_process_ids.user_ids.ids)):
                 category_approver.append((0, 0, {
                     'user_id': user,
                     'category_id': record.id