diff --git a/setuptools/package_index.py b/setuptools/package_index.py
index a66cbb2e613..dacfbccebf3 100644
--- a/setuptools/package_index.py
+++ b/setuptools/package_index.py
@@ -18,6 +18,7 @@
 import urllib.request
 from fnmatch import translate
 from functools import wraps
+from typing import NamedTuple
 
 from more_itertools import unique_everseen
 
@@ -1001,21 +1002,14 @@ def _encode_auth(auth):
     return encoded.replace('\n', '')
 
 
-class Credential:
-    """
-    A username/password pair. Use like a namedtuple.
-    """
-
-    def __init__(self, username, password):
-        self.username = username
-        self.password = password
+class Credential(NamedTuple):
+    """A username/password pair."""
 
-    def __iter__(self):
-        yield self.username
-        yield self.password
+    username: str
+    password: str
 
-    def __str__(self):
-        return '%(username)s:%(password)s' % vars(self)
+    def __str__(self) -> str:
+        return f'{self.username}:{self.password}'
 
 
 class PyPIConfig(configparser.RawConfigParser):