diff --git a/tornado/web.py b/tornado/web.py
index 905621c2..af5ea512 100644
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -500,10 +500,8 @@ class RequestHandler(object):
         else:
             assert isinstance(status, int) and 300 <= status <= 399
         self.set_status(status)
-        # Remove whitespace
-        url = re.sub(br"[\x00-\x20]+", "", utf8(url))
         self.set_header("Location", urlparse.urljoin(utf8(self.request.uri),
-                                                     url))
+                                                     utf8(url)))
         self.finish()
 
     def write(self, chunk):