diff --git a/var/spack/repos/builtin/packages/parallelio/package.py b/var/spack/repos/builtin/packages/parallelio/package.py
index 0f3abc629e3..e0ec714058b 100644
--- a/var/spack/repos/builtin/packages/parallelio/package.py
+++ b/var/spack/repos/builtin/packages/parallelio/package.py
@@ -88,6 +88,7 @@ def cmake_args(self):
             define("GENF90_PATH", join_path(src, "genf90")),
             define_from_variant("BUILD_SHARED_LIBS", "shared"),
             define("PIO_ENABLE_EXAMPLES", False),
+            define_from_variant("WITH_PNETCDF", "pnetcdf"),
         ]
         if spec.satisfies("+ncint"):
             args.extend([define("PIO_ENABLE_NETCDF_INTEGRATION", True)])