diff --git a/MANIFEST.in b/MANIFEST.in
index 4b08bae..9b2c42c 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,3 +1,4 @@
 include requirements/base.in
 include requirements/plugins.txt
 recursive-include tutor/templates *
+include tutor/py.typed
diff --git a/tutor/py.typed b/tutor/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/tutor/types.py b/tutor/types.py
index 973f580..e2a4469 100644
--- a/tutor/types.py
+++ b/tutor/types.py
@@ -35,7 +35,10 @@ T = t.TypeVar("T")
 
 
 def get_typed(
-    config: Config, key: str, expected_type: t.Type[T], default: t.Optional[T] = None
+    config: t.Dict[str, t.Any],
+    key: str,
+    expected_type: t.Type[T],
+    default: t.Optional[T] = None,
 ) -> T:
     value = config.get(key, default)
     if not isinstance(value, expected_type):