diff --git a/pyproject.toml b/pyproject.toml
index 3cea78a..c40bc9c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,6 +11,7 @@ classifiers = [
     "Intended Audience :: Developers",
     "Topic :: Software Development :: Build Tools",
     "Programming Language :: Python :: 3",
+     "Operating System :: POSIX :: Linux",
 ]
 dependencies = [
     "h5py",