diff --git a/lib/spack/spack/build_systems/nmake.py b/lib/spack/spack/build_systems/nmake.py
index b5e93755c5d..7b0f7f18baf 100644
--- a/lib/spack/spack/build_systems/nmake.py
+++ b/lib/spack/spack/build_systems/nmake.py
@@ -92,7 +92,7 @@ def makefile_root(self):
         This path is relative to the root of the extracted tarball,
         not to the ``build_directory``. Defaults to the current directory.
         """
-        return self.stage.source_dir
+        return self.stage.source_path
 
     @property
     def nmakefile_name(self):