diff --git a/inertia/py.typed b/inertia/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/inertia/tests/test_typing.py b/inertia/tests/test_typing.py
new file mode 100644
index 0000000..73fdb68
--- /dev/null
+++ b/inertia/tests/test_typing.py
@@ -0,0 +1,13 @@
+from pathlib import Path
+from unittest import TestCase
+
+
+class PyTypedTestCase(TestCase):
+    def test_py_typed_marker_exists(self):
+        """Verify that the py.typed marker file exists for PEP 561 compliance."""
+        package_dir = Path(__file__).resolve().parent.parent
+        py_typed = package_dir / "py.typed"
+        self.assertTrue(
+            py_typed.exists(),
+            f"py.typed marker file is missing from {package_dir}",
+        )