diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 883b2df3fb1..7f119a1edff 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -29,7 +29,7 @@ let
 
 in {
 
-  inherit python bootstrapped-pip isPy26 isPy27 isPy33 isPy34 isPy35 isPy36 isPyPy isPy3k mkPythonDerivation buildPythonPackage buildPythonApplication;
+  inherit python bootstrapped-pip pythonAtLeast pythonOlder isPy26 isPy27 isPy33 isPy34 isPy35 isPy36 isPyPy isPy3k mkPythonDerivation buildPythonPackage buildPythonApplication;
 
   # helpers