diff --git a/obmc-rest b/obmc-rest
index f655599..017a736 100644
--- a/obmc-rest
+++ b/obmc-rest
@@ -509,7 +509,7 @@
 			response_object['data']['traceback'] = error.traceback.splitlines()
 
 		json_response = json.dumps(response_object, **self.json_opts)
-		res.content_type = 'application/json'
+		response.content_type = 'application/json'
 		return json_response
 
 class RestApp(Bottle):