diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 39ff1f0f26c9..920772d47333 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -12,14 +12,14 @@ let
 let
   pythonAtLeast = versionAtLeast python.pythonVersion;
   pythonOlder = versionOlder python.pythonVersion;
-  isPy26 = python.majorVersion == "2.6";
-  isPy27 = python.majorVersion == "2.7";
-  isPy33 = python.majorVersion == "3.3";
-  isPy34 = python.majorVersion == "3.4";
-  isPy35 = python.majorVersion == "3.5";
-  isPy36 = python.majorVersion == "3.6";
+  isPy26 = python.pythonVersion == "2.6";
+  isPy27 = python.pythonVersion == "2.7";
+  isPy33 = python.pythonVersion == "3.3";
+  isPy34 = python.pythonVersion == "3.4";
+  isPy35 = python.pythonVersion == "3.5";
+  isPy36 = python.pythonVersion == "3.6";
   isPyPy = python.executable == "pypy";
-  isPy3k = strings.substring 0 1 python.majorVersion == "3";
+  isPy3k = strings.substring 0 1 python.pythonVersion == "3";
 
   callPackage = pkgs.newScope self;