diff -r 1554bd50a1af -r b52f2b365eff mercurial/httppeer.py
--- a/mercurial/httppeer.py	Mon Dec 16 02:41:24 2024 -0500
+++ b/mercurial/httppeer.py	Mon Dec 16 03:04:44 2024 -0500
@@ -13,6 +13,7 @@
 import os
 import socket
 import struct
+import typing
 
 from concurrent import futures
 from .i18n import _
@@ -28,6 +29,11 @@
 )
 from .utils import urlutil
 
+if typing.TYPE_CHECKING:
+    from typing import (
+        Set,
+    )
+
 httplib = util.httplib
 urlerr = util.urlerr
 urlreq = util.urlreq
@@ -439,7 +445,7 @@
 
     # Begin of ipeercapabilities interface.
 
-    def capabilities(self):
+    def capabilities(self) -> Set[bytes]:
         return self._caps
 
     # End of ipeercapabilities interface.