diff --git a/Lib/annotationlib.py b/Lib/annotationlib.py
index 42f1f3877514d9..d51369d0cc057d 100644
--- a/Lib/annotationlib.py
+++ b/Lib/annotationlib.py
@@ -20,7 +20,8 @@
 ]
 
 
-class Format(enum.IntEnum):
+@enum._simple_enum(enum.IntEnum)
+class Format:
     VALUE = 1
     VALUE_WITH_FAKE_GLOBALS = 2
     FORWARDREF = 3
diff --git a/Lib/test/test_annotationlib.py b/Lib/test/test_annotationlib.py
index 495606b48ed2e8..f757b12233f965 100644
--- a/Lib/test/test_annotationlib.py
+++ b/Lib/test/test_annotationlib.py
@@ -3,6 +3,7 @@
 import annotationlib
 import builtins
 import collections
+import enum
 import functools
 import itertools
 import pickle
@@ -51,6 +52,14 @@ def test_enum(self):
         self.assertEqual(Format.STRING.value, 4)
         self.assertEqual(Format.STRING, 4)
 
+    def test_simple_enum(self):
+        class Format(enum.IntEnum):
+            VALUE = 1
+            VALUE_WITH_FAKE_GLOBALS = 2
+            FORWARDREF = 3
+            STRING = 4
+        enum._test_simple_enum(Format, annotationlib.Format)
+
 
 class TestForwardRefFormat(unittest.TestCase):
     def test_closure(self):