diff --git a/apps/pm/views.py b/apps/pm/views.py
index a1c8ce7c..d63e30b8 100644
--- a/apps/pm/views.py
+++ b/apps/pm/views.py
@@ -211,7 +211,7 @@ class MtaskViewSet(CustomModelViewSet):
     @transaction.atomic
     def add_mtaskb(self, request, *args, **kwargs):
         mtask = self.get_object()
-        sr = MtaskAddInfoSerializer(data=request.data, many=True)
+        sr = MtaskbAddSerializer(data=request.data, many=True)
         sr.is_valid(raise_exception=True)
         vdata = sr.validated_data
         total = 0