From 82d4b2083292659358d5df4d03d2115576e8ae4e Mon Sep 17 00:00:00 2001
From: Timo Tuominen <tituomin@gmail.com>
Date: Mon, 1 Sep 2014 12:17:36 +0300
Subject: [PATCH] Add subclass matching to serializer field mapping.

---
 rest_framework/serializers.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index be8ad3f24..6d25161e2 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -907,6 +907,9 @@ class ModelSerializer(Serializer):
         try:
             return self.field_mapping[model_field.__class__](**kwargs)
         except KeyError:
+            for model_field_class, serializer_field_class in self.field_mapping.items():
+                if isinstance(model_field, model_field_class):
+                    return serializer_field_class(**kwargs)
             return ModelField(model_field=model_field, **kwargs)
 
     def get_validation_exclusions(self, instance=None):