diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index c2b414d7a..590b08bda 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -1014,6 +1014,9 @@ class ModelSerializer(Serializer):
         if getattr(obj, '_m2m_data', None):
             for accessor_name, object_list in obj._m2m_data.items():
                 setattr(obj, accessor_name, object_list)
+                if hasattr(obj, '_prefetched_objects_cache')\
+                        and accessor_name in obj._prefetched_objects_cache:
+                    obj._prefetched_objects_cache[accessor_name] = object_list
             del(obj._m2m_data)
 
         if getattr(obj, '_related_data', None):