diff --git a/pkgs/development/python-modules/twisted/default.nix b/pkgs/development/python-modules/twisted/default.nix
index 1a78e3afd0d..1c91dfc2b48 100644
--- a/pkgs/development/python-modules/twisted/default.nix
+++ b/pkgs/development/python-modules/twisted/default.nix
@@ -2,6 +2,7 @@
 , buildPythonPackage
 , fetchPypi
 , python
+, isPy27
 , zope_interface
 , incremental
 , automat
@@ -17,6 +18,7 @@
 buildPythonPackage rec {
   pname = "Twisted";
   version = "19.7.0";
+  disabled = isPy27; # ruamel namespace now conflicts in python27
 
   src = fetchPypi {
     inherit pname version;