diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index cec87e881..01b62a089 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -11,7 +11,7 @@ python primitives.
 response content is handled by parsers and renderers.
 """
 from __future__ import unicode_literals
-
+import re
 import copy
 import inspect
 import traceback