diff --git a/apps/wpm/serializers.py b/apps/wpm/serializers.py
index 210e9376..925f87ff 100644
--- a/apps/wpm/serializers.py
+++ b/apps/wpm/serializers.py
@@ -289,6 +289,11 @@ class MlogSerializer(CustomModelSerializer):
 
     def validate(self, attrs):
         mtask = attrs.get('mtask', None)
+        count_notok = 0
+        for i in attrs:
+            if 'count_n_' in i:
+                count_notok = count_notok + attrs[i]
+        attrs['count_notok'] = count_notok
         if mtask:
             if mtask.start_date == mtask.end_date:
                 attrs['handle_date'] = mtask.start_date