diff --git a/pkgs/applications/science/misc/root/default.nix b/pkgs/applications/science/misc/root/default.nix
index 990952e21aca..97d8d4e7cee5 100644
--- a/pkgs/applications/science/misc/root/default.nix
+++ b/pkgs/applications/science/misc/root/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, makeWrapper, cmake, gl2ps, gsl, libX11, libXpm, libXft
+{ stdenv, lib, fetchurl, makeWrapper, cmake, gl2ps, gsl, libX11, libXpm, libXft
 , libXext, libGLU, libGL, libxml2, lz4, lzma, pcre, pkgconfig, python, xxHash
 , zlib
 , Cocoa, OpenGL, noSplash ? false }:
@@ -13,11 +13,10 @@ stdenv.mkDerivation rec {
   };
 
   nativeBuildInputs = [ makeWrapper cmake pkgconfig ];
-  buildInputs = [ gl2ps pcre python zlib libxml2 lz4 lzma gsl xxHash ]
-    ++ stdenv.lib.optionals (!stdenv.isDarwin) [ libX11 libXpm libXft libXext libGLU libGL ]
-    ++ stdenv.lib.optionals (stdenv.isDarwin) [ Cocoa OpenGL ]
+  buildInputs = [ gl2ps pcre zlib libxml2 lz4 lzma gsl xxHash python.pkgs.numpy ]
+    ++ lib.optionals (!stdenv.isDarwin) [ libX11 libXpm libXft libXext libGLU libGL ]
+    ++ lib.optionals (stdenv.isDarwin) [ Cocoa OpenGL ]
     ;
-  propagatedBuildInputs = [ python.pkgs.numpy ];
 
   patches = [
     ./sw_vers.patch