diff --git a/Lib/test/test_email/test__header_value_parser.py b/Lib/test/test_email/test__header_value_parser.py
index 646082b..32996ca 100644
--- a/Lib/test/test_email/test__header_value_parser.py
+++ b/Lib/test/test_email/test__header_value_parser.py
@@ -540,6 +540,15 @@
         self._test_get_x(parser.get_bare_quoted_string,
             '""', '""', '', [], '')
 
+    # Issue 16983: apply postel's law to some bad encoding.
+    def test_encoded_word_inside_quotes(self):
+        self._test_get_x(parser.get_bare_quoted_string,
+            '"=?utf-8?Q?not_really_valid?="',
+            '"not really valid"',
+            'not really valid',
+            [errors.InvalidHeaderDefect],
+            '')
+
     # get_comment
 
     def test_get_comment_only(self):
diff --git a/Lib/test/test_email/test_headerregistry.py b/Lib/test/test_email/test_headerregistry.py
index f829f83..adaf3e8 100644
--- a/Lib/test/test_email/test_headerregistry.py
+++ b/Lib/test/test_email/test_headerregistry.py
@@ -1143,6 +1143,16 @@
             'example.com',
             None),
 
+        'rfc2047_atom_in_quoted_string_is_decoded':
+            ('"=?utf-8?q?=C3=89ric?=" <foo@example.com>',
+            [errors.InvalidHeaderDefect],
+            'Éric <foo@example.com>',
+            'Éric',
+            'foo@example.com',
+            'foo',
+            'example.com',
+            None),
+
         }
 
         # XXX: Need many more examples, and in particular some with names in