diff --git a/lib/spack/spack/build_systems/python.py b/lib/spack/spack/build_systems/python.py
index 60a850d356..d2ee72925d 100644
--- a/lib/spack/spack/build_systems/python.py
+++ b/lib/spack/spack/build_systems/python.py
@@ -112,7 +112,7 @@ def python(self, *args):
     def setup_py(self, *args):
         setup = self.setup_file()
 
-        with working_dir(self.build_directory()):
+        with working_dir(self.build_directory):
             self.python(setup, '--no-user-cfg', *args)
 
     # The following phases and their descriptions come from: