diff --git a/setup.py b/setup.py
index 57e1cac..88959e5 100644
--- a/setup.py
+++ b/setup.py
@@ -12,6 +12,9 @@
     entry_points = {
         "console_scripts": ["yangson=yangson.__main__:main"]
         },
+    package_data = {
+        "yangson": ["py.typed"]
+        },
     install_requires = ["PyXB"],
     tests_require = ["pytest"],
     keywords = ["yang", "data model", "configuration", "json"],
diff --git a/yangson/py.typed b/yangson/py.typed
new file mode 100644
index 0000000..33ab0a1
--- /dev/null
+++ b/yangson/py.typed
@@ -0,0 +1 @@
+PEP 561 marker file