diff --git a/myst_parser/mocking.py b/myst_parser/mocking.py
index 3a739906..61a2b172 100644
--- a/myst_parser/mocking.py
+++ b/myst_parser/mocking.py
@@ -353,7 +353,7 @@ def __init__(
         self,
         renderer: DocutilsRenderer,
         name: str,
-        klass: Include,
+        klass: type[Include],
         arguments: list[str],
         options: dict[str, Any],
         body: list[str],