diff --git a/var/spack/repos/builtin/packages/sz/package.py b/var/spack/repos/builtin/packages/sz/package.py
index b06e1c099d8..ca1ced87ee1 100644
--- a/var/spack/repos/builtin/packages/sz/package.py
+++ b/var/spack/repos/builtin/packages/sz/package.py
@@ -93,6 +93,7 @@ def cmake_args(self):
 
         if "+python" in self.spec:
             args.append("-DBUILD_PYTHON_WRAPPER=ON")
+            args.append("-DSZ_PYTHON_SITELIB={0}".format(site_packages_dir))
         else:
             args.append("-DBUILD_PYTHON_WRAPPER=OFF")