diff --git a/pkgs/tools/filesystems/nixpart/0.4/pykickstart.nix b/pkgs/tools/filesystems/nixpart/0.4/pykickstart.nix
index 8a1fce78037..9d067359c44 100644
--- a/pkgs/tools/filesystems/nixpart/0.4/pykickstart.nix
+++ b/pkgs/tools/filesystems/nixpart/0.4/pykickstart.nix
@@ -19,7 +19,6 @@ buildPythonApplication rec {
   propagatedBuildInputs = [ urlgrabber ];
 
   checkPhase = ''
-    export PYTHONPATH="$PYTHONPATH:."
     ${python}/bin/${python.executable} tests/baseclass.py -vv
   '';