User SimpleUserSeriliazer on stats

courses/stats/serializers.py

 from rest_framework import serializers
 from actstream.models import Action
 from courses.reports.serializers import UserStatsSerializer
+from courses.serializers import SimpleUserSerializer
 
 from django.contrib.auth.models import User
 from django.contrib.auth import get_user_model
@@ -25,7 +26,7 @@ class UserAccessSerializer(serializers.Serializer):
 class GenericRelatedField(serializers.Field):
     def to_representation(self, value):
         if isinstance(value, User):
-            return UserStatsSerializer(value).data
+            return SimpleUserSerializer(value).data
         if isinstance(value, Classroom):
             return BasicClassroomSerializer(value).data
         return str(value)