From b0c7eb9ce8bfe48b11075f7c8eba78bd0adc666b Mon Sep 17 00:00:00 2001
From: Randolf Scholz <randolf.scholz@gmail.com>
Date: Thu, 14 May 2026 17:29:07 +0200
Subject: [PATCH 1/2] gh-119946: make Protocol compatible with Enum
 instantiation

---
 Lib/test/test_enum.py | 20 ++++++++++++++++++++
 Lib/typing.py         |  6 +++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 779457119e8f0e..ad7ab1ab3d4534 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -2478,6 +2478,26 @@ class SomeEnum(Enum):
         globals()['T'] = T
         test_pickle_dump_load(self.assertIs, SomeEnum.first)
 
+    def test_protocol_mixin_as_enum_member_value(self):
+        class Example(typing.Protocol):
+            def method(self) -> None: ...
+
+        class Impl(Example):
+            def method(self) -> None: ...
+
+        class CompatEnumType(type(typing.Protocol), EnumType): ...
+
+        class ProtoEnum(Example, Enum, metaclass=CompatEnumType):
+            __qualname__ = 'ProtoEnum'  # needed for pickle protocol 4
+            impl = Impl()
+
+        self.assertIsInstance(ProtoEnum.impl.value, Impl)
+        globals()['Example'] = Example
+        globals()['Impl'] = Impl
+        globals()['ProtoEnum'] = ProtoEnum
+        ProtoEnum.__reduce_ex__ = enum.pickle_by_enum_name
+        test_pickle_dump_load(self.assertIs, ProtoEnum.impl)
+
     def test_duplicate_values_give_unique_enum_items(self):
         class AutoNumber(Enum):
             first = ()
diff --git a/Lib/typing.py b/Lib/typing.py
index 130e09be4b9127..7e86c911758c11 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1882,7 +1882,11 @@ def _get_protocol_attrs(cls):
 def _no_init_or_replace_init(self, *args, **kwargs):
     cls = type(self)
 
-    if cls._is_protocol:
+    # Determine if this is a protocol or a concrete subclass.
+    # Note: not using cls._is_protocol here,
+    #  since this may be called before __init_subclass__ is resolved.
+    #  for example when subclassing enum.Enum.
+    if any(b is Protocol for b in cls.__bases__):
         raise TypeError('Protocols cannot be instantiated')
 
     # Already using a custom `__init__`. No need to calculate correct

From 5ab82ba0d607a9639d47d674cd382b68aa296969 Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Thu, 14 May 2026 15:44:30 +0000
Subject: [PATCH 2/2] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../next/Library/2026-05-14-15-44-25.gh-issue-149828.ADCPIl.rst  | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Library/2026-05-14-15-44-25.gh-issue-149828.ADCPIl.rst

diff --git a/Misc/NEWS.d/next/Library/2026-05-14-15-44-25.gh-issue-149828.ADCPIl.rst b/Misc/NEWS.d/next/Library/2026-05-14-15-44-25.gh-issue-149828.ADCPIl.rst
new file mode 100644
index 00000000000000..ae99d03eed5aca
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-05-14-15-44-25.gh-issue-149828.ADCPIl.rst
@@ -0,0 +1 @@
+Fixed an issue that prevented creation of an :class:`enum.Enum` that inherits from a subclass :class:`typing.Protocol`.