diff --git a/Lib/enum.py b/Lib/enum.py
index 0c2cf56..060b2a0 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -629,7 +629,7 @@
 
     @classmethod
     def _missing_(cls, value):
-        raise ValueError("%r is not a valid %s" % (value, cls.__qualname__))
+        return None
 
     def __repr__(self):
         return "<%s.%s: %r>" % (
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 2fcd047..5d72d82 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -1845,6 +1845,18 @@
             third = auto()
         self.assertEqual([Dupes.first, Dupes.second, Dupes.third], list(Dupes))
 
+    def test_default_missing(self):
+        class Color(Enum):
+            RED = 1
+            GREEN = 2
+            BLUE = 3
+        try:
+            Color(7)
+        except ValueError as exc:
+            self.assertTrue(exc.__context__ is None)
+        else:
+            raise Exception('Exception not raised.')
+
     def test_missing(self):
         class Color(Enum):
             red = 1
@@ -1863,7 +1875,12 @@
                     # trigger not found
                     return None
         self.assertIs(Color('three'), Color.blue)
-        self.assertRaises(ValueError, Color, 7)
+        try:
+            Color(7)
+        except ValueError as exc:
+            self.assertTrue(exc.__context__ is None)
+        else:
+            raise Exception('Exception not raised.')
         try:
             Color('bad return')
         except TypeError as exc:
diff --git a/Misc/ACKS b/Misc/ACKS
index 8b0d7a4..2628d6b 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -433,6 +433,7 @@
 Dima Dorfman
 Yves Dorfsman
 Michael Dorman
+Andrey Doroschenko
 Steve Dower
 Allen Downey
 Cesar Douady
diff --git a/Misc/NEWS.d/next/Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst b/Misc/NEWS.d/next/Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst
new file mode 100644
index 0000000..beb2016
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-02-24-10-58-34.bpo-39728.kOOaHn.rst
@@ -0,0 +1 @@
+fix default `_missing_` so a duplicate `ValueError` is not set as the `__context__` of the original `ValueError`