diff --git a/textproc/py-sphinx/Makefile b/textproc/py-sphinx/Makefile
index 18d37bfdab742..ff770294de6a9 100644
--- a/textproc/py-sphinx/Makefile
+++ b/textproc/py-sphinx/Makefile
@@ -2,6 +2,7 @@
 
 PORTNAME=	sphinx
 PORTVERSION=	3.5.2
+PORTREVISION=	1
 PORTEPOCH=	1
 CATEGORIES=	textproc python
 MASTER_SITES=	CHEESESHOP
diff --git a/textproc/py-sphinx/files/patch-sphinx_util_typing.py b/textproc/py-sphinx/files/patch-sphinx_util_typing.py
new file mode 100644
index 0000000000000..2b21fdd41d1a9
--- /dev/null
+++ b/textproc/py-sphinx/files/patch-sphinx_util_typing.py
@@ -0,0 +1,58 @@
+From 8b2031c747e7c7e6b845ee2e3db47de617d33cc6 Mon Sep 17 00:00:00 2001
+From: Takeshi KOMIYA <i.tkomiya@gmail.com>
+Date: Fri, 30 Jul 2021 01:27:38 +0900
+Subject: [PATCH] Fix #9512: sphinx-build: crashed with the HEAD of Python 3.10
+
+Recently, `types.Union` was renamed to `types.UnionType` on the HEAD
+of 3.10 (refs: python/cpython#27342). After this change, sphinx-build
+has been crashed because of ImportError.
+--- CHANGES.orig	2021-03-06 11:59:38 UTC
++++ CHANGES
+@@ -419,6 +419,8 @@ Bugs fixed
+ * #6914: figure numbers are unexpectedly assigned to uncaptioned items
+ * #8320: make "inline" line numbers un-selectable
+ 
++* #9512: sphinx-build: crashed with the HEAD of Python 3.10
++
+ Testing
+ --------
+ 
+ CHANGES               |  2 ++
+ sphinx/util/typing.py | 12 ++++++------
+ 2 files changed, 8 insertions(+), 6 deletions(-)
+
+--- sphinx/util/typing.py.orig	2021-03-06 11:58:24 UTC
++++ sphinx/util/typing.py
+@@ -30,10 +30,10 @@ else:
+             ref = _ForwardRef(self.arg)
+             return ref._eval_type(globalns, localns)
+ 
+-if sys.version_info > (3, 10):
+-    from types import Union as types_Union
+-else:
+-    types_Union = None
++try:
++    from types import UnionType  # type: ignore  # python 3.10 or above
++except ImportError:
++    UnionType = None
+ 
+ if False:
+     # For type annotation
+@@ -107,7 +107,7 @@ def restify(cls: Optional["Type"]) -> str:
+         return ':class:`struct.Struct`'
+     elif inspect.isNewType(cls):
+         return ':class:`%s`' % cls.__name__
+-    elif types_Union and isinstance(cls, types_Union):
++    elif UnionType and isinstance(cls, UnionType):
+         if len(cls.__args__) > 1 and None in cls.__args__:
+             args = ' | '.join(restify(a) for a in cls.__args__ if a)
+             return 'Optional[%s]' % args
+@@ -349,7 +349,7 @@ def _stringify_py37(annotation: Any) -> str:
+     elif hasattr(annotation, '__origin__'):
+         # instantiated generic provided by a user
+         qualname = stringify(annotation.__origin__)
+-    elif types_Union and isinstance(annotation, types_Union):  # types.Union (for py3.10+)
++    elif UnionType and isinstance(annotation, UnionType):  # types.Union (for py3.10+)
+         qualname = 'types.Union'
+     else:
+         # we weren't able to extract the base type, appending arguments would