diff --git a/Lib/test/test_imaplib.py b/Lib/test/test_imaplib.py
index c613d699f085ae..bbd6f173c945d0 100644
--- a/Lib/test/test_imaplib.py
+++ b/Lib/test/test_imaplib.py
@@ -1616,6 +1616,16 @@ def test_xatom(self):
         self.assertEqual(data, [b'MYCOMMAND completed'])
         self.assertEqual(server.args, ['arg1', 'arg2'])
 
+    def test_uppercase_command_names(self):
+        client, server = self._setup(SimpleIMAPHandler)
+        client.login('user', 'pass')
+        self.assertEqual(client.CAPABILITY, client.capability)
+        self.assertEqual(client.SELECT, client.select)
+        typ, data = client.CAPABILITY()
+        self.assertEqual(typ, 'OK')
+        with self.assertRaises(AttributeError):
+            client.NONEXISTENT
+
 
 class NewIMAPTests(NewIMAPTestsMixin, unittest.TestCase):
     imap_class = imaplib.IMAP4