diff --git a/pkgs/development/python-modules/gurobipy/darwin.nix b/pkgs/development/python-modules/gurobipy/darwin.nix
index 95a59bf44c7..9d7374bd5bd 100644
--- a/pkgs/development/python-modules/gurobipy/darwin.nix
+++ b/pkgs/development/python-modules/gurobipy/darwin.nix
@@ -1,5 +1,5 @@
 { stdenv, fetchurl, python, xar, cpio, cctools, insert_dylib }:
-assert python.isPy27 && python.ucsEncoding == 2;
+assert python.pkgs.isPy27 && python.ucsEncoding == 2;
 stdenv.mkDerivation
   { name = "gurobipy-7.0.2";
     src = fetchurl
diff --git a/pkgs/development/python-modules/gurobipy/linux.nix b/pkgs/development/python-modules/gurobipy/linux.nix
index fa4d58c77b7..f65ae4a2ed2 100644
--- a/pkgs/development/python-modules/gurobipy/linux.nix
+++ b/pkgs/development/python-modules/gurobipy/linux.nix
@@ -1,12 +1,10 @@
 { stdenv, fetchurl, python }:
-assert python.isPy27;
-let utf = if python.ucsEncoding == 2
-            then "16"
-          else if python.ucsEncoding == 4
-            then "32"
-          else throw "Unsupported python UCS encoding UCS${toString python.ucsEncoding}";
-in
-stdenv.mkDerivation
+assert python.pkgs.isPy27;
+let utf =
+  if python.ucsEncoding == 2 then "16"
+  else if python.ucsEncoding == 4 then "32"
+  else throw "Unsupported python UCS encoding UCS${toString python.ucsEncoding}";
+in stdenv.mkDerivation
   { name = "gurobipy-7.0.2";
     src = fetchurl
       { url = "http://packages.gurobi.com/7.0/gurobi7.0.2_linux64.tar.gz";
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index d99a7168a11..075b33cd087 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -5631,11 +5631,11 @@ in {
   };
 
   gurobipy = if stdenv.system == "x86_64-darwin"
-    then callPackage ../development/python-modules/gurobipy/darwin.nix
-           { inherit (pkgs.darwin) cctools insert_dylib;
-           }
+  then callPackage ../development/python-modules/gurobipy/darwin.nix {
+    inherit (pkgs.darwin) cctools insert_dylib;
+  }
   else if stdenv.system == "x86_64-linux"
-    then callPackage ../development/python-modules/gurobipy/linux.nix {}
+  then callPackage ../development/python-modules/gurobipy/linux.nix {}
   else throw "gurobipy not yet supported on ${stdenv.system}";
 
   helper = buildPythonPackage rec {