diff --git a/doc-py38-to-py36.patch b/doc-py38-to-py36.patch
index 84eec6b..0f352e2 100644
--- a/doc-py38-to-py36.patch
+++ b/doc-py38-to-py36.patch
@@ -78,7 +78,7 @@
 -from typing import TYPE_CHECKING
  
  from docutils import nodes
-+from typing import Any, List, Tuple
++from typing import Any, List, Set, Tuple
  from sphinx.errors import NoUri
  from sphinx.locale import _ as sphinx_gettext
  from sphinx.transforms.post_transforms import SphinxPostTransform