diff --git a/pkgs/development/python-modules/nose/default.nix b/pkgs/development/python-modules/nose/default.nix
index 451c71897da9..586af7a90423 100644
--- a/pkgs/development/python-modules/nose/default.nix
+++ b/pkgs/development/python-modules/nose/default.nix
@@ -23,7 +23,9 @@ buildPythonPackage rec {
       --replace "from setuptools.command.build_py import Mixin2to3" "from distutils.util import Mixin2to3"
   '';
 
-  preBuild = ''
+  preBuild = lib.optionalString
+      ((python.isPy3k or false) && (python.pname != "pypy3"))
+  ''
     2to3 -wn nose functional_tests unit_tests
   '';