diff --git a/pkgs/development/python-modules/tornado/default.nix b/pkgs/development/python-modules/tornado/default.nix
index d446d377e66..1d8a03578cd 100644
--- a/pkgs/development/python-modules/tornado/default.nix
+++ b/pkgs/development/python-modules/tornado/default.nix
@@ -42,6 +42,8 @@ buildPythonPackage rec {
     inherit pname sha256 version;
   };
 
+  __darwinAllowLocalNetworking = true;
+
   meta = {
     description = "A web framework and asynchronous networking library";
     homepage = http://www.tornadoweb.org/;