diff --git a/www/conservancy/middleware.py b/www/conservancy/middleware.py
index 7abbac7b632766237c9ed2c6166248a8fca9c853..cafa5bc8086faa8d574ae330bfc1b06fc61d665f 100644
--- a/www/conservancy/middleware.py
+++ b/www/conservancy/middleware.py
@@ -1,5 +1,4 @@
 from builtins import object
-from future.utils import raise_
 from django import http
 from django.conf import settings
 from django.utils.cache import patch_response_headers
@@ -29,7 +28,7 @@ class ForceCanonicalHostnameMiddleware(object):
         if settings.APPEND_SLASH and (old_url[1][-1] != '/') and ('.' not in old_url[1].split('/')[-1]):
             new_url[1] = new_url[1] + '/'
             if settings.DEBUG and request.method == 'POST':
-                raise_(RuntimeError, "You called this URL via POST, but the URL doesn't end in a slash and you have APPEND_SLASH set. Django can't redirect to the slash URL while maintaining POST data. Change your form to point to %s%s (note the trailing slash), or set APPEND_SLASH=False in your Django settings." % (new_url[0], new_url[1]))
+                raise(RuntimeError, "You called this URL via POST, but the URL doesn't end in a slash and you have APPEND_SLASH set. Django can't redirect to the slash URL while maintaining POST data. Change your form to point to %s%s (note the trailing slash), or set APPEND_SLASH=False in your Django settings." % (new_url[0], new_url[1]))
         # Strip trailing index.html
         if new_url[1].endswith('/index.html'):
             new_url[1] = new_url[1][:new_url[1].rfind('index.html')]