diff --git a/requests/models.py b/requests/models.py
index 752c58c1..caf13d66 100644
--- a/requests/models.py
+++ b/requests/models.py
@@ -42,12 +42,11 @@ REDIRECT_STATI = (
     codes.temporary_redirect, # 307
     codes.permanent_redirect, # 308
 )
+
 DEFAULT_REDIRECT_LIMIT = 30
 CONTENT_CHUNK_SIZE = 10 * 1024
 ITER_CHUNK_SIZE = 512
 
-json_dumps = json.dumps
-
 
 class RequestEncodingMixin(object):
     @property
@@ -425,7 +424,7 @@ class PreparedRequest(RequestEncodingMixin, RequestHooksMixin):
 
         if json is not None:
             content_type = 'application/json'
-            body = json_dumps(json)
+            body = json.dumps(json)
 
         is_stream = all([
             hasattr(data, '__iter__'),